Born in a naval hospital on Long Island, New York, Keyes was the fifth child to Allison and Gerthina Keyes, a U.S. Army sergeant and a teacher. Due to his father's tours of duty, the Keyes family traveled frequently. Keyes lived in Georgia, Maryland, New Jersey, New York, Texas, Virginia and overseas in Italy.

After high school, Keyes attended Cornell University, where he was a member of the Cornell University Glee Club and The Hangovers. He studied political philosophy with American philosopher and essayist Allan Bloom and has said that Bloom was the professor who influenced him most in his undergraduate studies. Later, Keyes received death threats for opposing Vietnam war protesters who seized a campus building. Keyes has stated that a passage of Bloom's book, The Closing of the American Mind, refers to this incident, speaking of an African-American student "whose life had been threatened by a black faculty member when the student refused to participate in a demonstration" at Cornell. Shortly thereafter, he left the school and spent a year in Paris under a Cornell study abroad program connected with Bloom.

Keyes continued his studies at Harvard University, where he resided in Winthrop House, and completed his Bachelor of Arts degree in government affairs in 1972. During his first year of graduate school, Keyes's roommate was William Kristol. In 1988, Kristol ran Keyes's unsuccessful U.S. Senate campaign in Maryland.

Keyes earned his PhD in government affairs from Harvard University in 1979, having written a dissertation on Alexander Hamilton and constitutional theory, under Harvey C. Mansfield. Due to student deferments and a high draft number, Keyes was not drafted to serve in the Vietnam War. Keyes and his family were staunch supporters of the war, in which his father served two tours of duty. Keyes was criticized by opponents of the war in Vietnam, but he says he was supporting his father and his brothers, who were also fighting in the war.

Keyes is married to Jocelyn Marcel Keyes, of Indian descent, from Calcutta. The couple has three children, Francis, Maya, and Andrew. Keyes is a traditional Catholic and a third-degree Knight of Columbus.

In 2005, when Maya Keyes was 20-years-old, she came out as a lesbian. There were reports her family threw her out of the house and stopped talking to her. In an interview with, Metro Weekly, a Washington, D.C., LGBT newspaper, Maya confirmed that her father, "cut off all financial support." In the same report Maya said, "It doesn't make much sense for him to be [financially] supporting someone who is working against what he believes in." Alan Keyes contradicted reports about his having disowned his daughter in October 2007. In response to a caller, Keyes said that he loves his daughter and that she knows she has a home with him. He asserted that he never cut her off and never would, because it would be, "wrong in the eyes of God." He also said he would not be coerced into "approving of that which destroys the soul" of his daughter. He contended that he must "stand for the truth [Jesus Christ] represents" even if it breaks his heart.

On May 8, 2009, Keyes and 21 others were arrested while protesting President Barack Obama's commencement speech at the University of Notre Dame. Keyes was charged with trespassing and released on $250 bond. He was arrested a second time on May 16.

A year before completing his doctoral studies, Keyes joined the United States Department of State as a protégé of UN Ambassador Jeane Kirkpatrick. In 1979, he was assigned to the consulate in Mumbai, India, where, as a desk officer, he met his wife Jocelyn Marcel. The following year, Keyes was sent to serve at the embassy in Zimbabwe.

In 1983, President Ronald Reagan appointed Keyes as Ambassador to the United Nations Economic and Social Council. In 1985, he was appointed Assistant Secretary of State for International Organizations, a position he held until 1987. His stay at the UN provoked some controversy, leading Newsday to say "he has propounded the more unpopular aspects of US policy with all the diplomatic subtlety of the cannon burst in Tchaikovsky's 1812 Overture." He also served on the staff of the National Security Council.

At a fundraiser for Keyes's senate campaign, President Reagan spoke of Keyes's time as an ambassador, saying that he "did such an extraordinary job ... defending our country against the forces of anti-Americanism." Reagan continued, "I've never known a more stout-hearted defender of a strong America than Alan Keyes." In 1987 Keyes was appointed a resident scholar for the American Enterprise Institute. His principal research for AEI was diplomacy, international relations, and self-government.

Following government service, Ambassador Keyes was President of Citizens Against Government Waste (CAGW) from 1989 to 1991, and founded CAGW's National Taxpayers' Action Day. In 1991, he served as Interim President of Alabama A&M University, in Huntsville, Alabama.

Among the U.S. delegation to the 1984 World Population Conference in Mexico City, Keyes was selected by Reagan as deputy chairman. In that capacity, Keyes negotiated the language of the Mexico City Policy to withhold federal funds from international organizations that support abortion. Additionally, Keyes fought against an Arab-backed U.N. resolution calling for investigation of Israeli settlements. The measure passed 83-2, with 15 abstentions and only Israel and the U.S. voting against it. Reagan again appointed Keyes to represent the U.S. at the 1985 Women's Conference in Nairobi.

During his time at the United States Department of State, Keyes defended the Reagan policy of not imposing economic sanctions on South Africa as punishment for apartheid. Stated Keyes, "I see the black people in South Africa as the most critical positive factor for eliminating apartheid and building the future of that country ... And that is not something you do with rhetoric, slogans and noninvolvement. It's not something you will achieve through disinvestment."

1988 Senate election

In 1988, Keyes was drafted by the Maryland Republican Party to run for the United States Senate, and received 38 percent of the vote against victorious incumbent Democrat Paul Sarbanes.

1992 Senate election

Four years later, he ran again for the Senate from Maryland, coming in first in a field of 13 candidates in the Republican primary. Against Democrat Barbara Mikulski, he received 29 percent in the general election.

During the 1992 election, Keyes attracted controversy when he took a $8,463/month salary from his campaign fund.

1996 Presidential election

Keyes sought the Republican presidential nomination in 1996, in an effort to force abortion to the center of America's public policy debate. Many Republican leaders saw this as unnecessary and divisive. Keyes was particularly critical of Clinton during his campaign, saying, "This guy lies, but he lies with passion." He questioned whether a Republican candidate who is truthful, yet cold and heartless, had a chance to win against the incumbent.Keyes was also especially critical of Pat Buchanan, once saying during an interview on the Talk from the Heart program with Al Kresta (simulcast on KJSL-AM St. Louis and WMUZ-FM Detroit) that Buchanan had a "black heart." Keyes's entry into the Republican race after Buchanan had secured victories in New Hampshire and Louisiana led many to believe that Keyes was a stalking horse for neoconservative elements in the G.O.P., since Buchanan had been a well-known ardent foe of abortion and had suffered political fallout for bringing abortion and "cultural war" to the center of the public policy debate. Later during the primaries, Keyes was briefly detained by Atlanta police when he tried to force his way into a debate to which he had been invited, and then uninvited. He was never formally arrested and was eventually picked up 20 minutes later by Atlanta's mayor at the time, Bill Campbell.

2000 Presidential election

Keyes again campaigned for the Republican nomination in the 2000 primaries on a pro-life, family values, tax reform plank. In Iowa, he finished 3rd, drawing 14 percent in a crowded field. He stayed in the race after the early rounds and debated the two remaining candidates, John McCain and George W. Bush, in a number of nationally televised debates. He finished second in 8 primaries. His best showing in the presidential primaries was in Utah, where he received 20 percent of the vote. He was also noted for jumping into a mosh pit during the Iowa caucus as part of a segment on Michael Moore's TV series The Awful Truth.

2004 Senate election

On August 8, 2004 — with 86 days to go before the general election — the Illinois Republican Party drafted Alan Keyes to run against Democratic Illinois Senate member and future President of The United States Barack Obama for the U.S. Senate, after the Republican nominee, Jack Ryan, withdrew due to a sex scandal, and other potential draftees (most notably former Chicago Bears coach Mike Ditka) declined to run. The Washington Post called Keyes a "carpetbagger" since he "had never lived in Illinois." When asked to answer charges of carpetbagging in the context of his earlier criticism of Hillary Clinton, he called her campaign "pure and planned selfish ambition", but stated that in his case he felt a moral obligation to run after being asked to by the state GOP. "You are doing what you believe to be required by your respect for God's will, and I think that that's what I'm doing in Illinois".

Keyes, who opposes abortion in all cases "except as an inadvertent result of efforts to save the mother's life",said in a September 7, 2004 news conference that Jesus Christ would not vote for Obama because of votes that Obama ... then a member of the Illinois Senate Judiciary committee and a lecturer in constitutional law at the University of Chicago Law School ...cast in 2001 against a package of three anti-abortion bills that Obama argued were too broad and unconstitutional. The legislation, which provided "that a live child born as a result of an abortion shall be fully recognized as a human person," passed the Republican-controlled Illinois Senate, but failed to pass out of theDemocratic-controlled Illinois House Judiciary committee. After the election, Keyes declined to congratulate Obama, explaining that his refusal to congratulate Obama was "not anything personal", but was meant to make a statement against "extend[ing] false congratulations to the triumph of what we have declared to be across the line" of reasonable propriety. He said that Obama's position on moral issues regarding life and the family had crossed that line. "I'm supposed to make a call that represents the congratulations toward the triumph of that which I believe ultimately stands for ... a culture evil enough to destroy the very soul and heart of my country? I cannot do this. And I will not make a false gesture," Keyes said.

Keyes was also criticized for his views on homosexuality. In an interview with Michelangelo Signorile, a gay radio host, Keyes defined homosexuality as centering in the pursuit of pleasure, literally "selfish hedonism". When Signorile asked if Mary Cheney, Vice President Dick Cheney's avowed lesbian daughter, fit the description and was therefore a "selfish hedonist", Keyes replied, "Of course she is. That goes by definition." Media sources picked up on the exchange, reporting that Keyes had "trashed", "attacked," and "lashed out at" Mary Cheney, and had called her a "sinner" — provoking condemnation of Keyes by gay Republicans and several GOP leaders. Keyes noted that it was an interviewer, not he, who brought up Mary Cheney's name in the above incident, and he told reporters, "You have tried to personalize the discussion of an issue that I did not personalize. The people asking me the question did so, and if that's inappropriate, blame the media. Do not blame me."

During the campaign, Keyes outlined an alternative to reparations for slavery. His specific suggestion was that, for a period of one or two generations, African-Americans who were descended from slaves would be exempt from the federal income tax (though not from the FICA tax that supports Social Security). Keyes said the experiment "would become a demonstration project for what I believe needs to be done for the whole country, which is to get rid of the income tax." He also called for the repeal of the 17th Amendment in order that US Senators should be appointed by state legislatures and no longer be directly elected.

Keyes finished with 27% of the vote despite winning a small number of southern Illinois counties.

2008 Presidential election

On June 5, 2007, We Need Alan Keyes for President was formed as a political action committee to encourage Keyes to enter the 2008 presidential election. On September 14, 2007, Keyes officially announced his candidacy in an interview with radio show host Janet Parshall. On September 17, 2007, Keyes participated in the Values Voter Debate streamed live on Skyangel, the Values Voter website, and radio. In a straw poll of the attending audience, Keyes placed third among the invited candidates, after Mike Huckabee and Ron Paul. Keyes was excluded from the Republican CNN/YouTube debate on November 28, 2007. Keyes's campaign called the exclusion "arbitrary, unfair, and presumptuous," arguing that CNN was playing the role of "gatekeeper" for the presidential election.

On December 12, 2007, Keyes participated in the Des Moines Register's Republican presidential debate, televised nationwide by PBS and the cable news networks. This was the first major presidential debate in which Keyes participated during the 2008 election season and the last Republican debate before the Iowa Caucuses. Although Keyes wasn't listed on the latest national CNN poll leading up to the debate, he registered with at least 1 percent of the Iowa vote in order to participate. During the debate, after the moderator began to ask a question of Texas Congressman Ron Paul, Keyes insisted he wasn't getting fair treatment. He interrupted the debate moderator at one point, saying that she hadn't called on him in several rounds and that he had to make an issue of it. He went on the offensive against his opponents during the debate, criticizing Rudy Giuliani's pro-choice position, as well as Mitt Romney's recent change in position on the same subject. In answering a question about global warming, he continued his criticisms of other candidates, saying, "I'm in favor of reducing global warming, because I think the most important emission we need to control is the hot air emission of politicians who pretend one thing and don't deliver". He also advocated ending the income tax, establishing state-sanctioned prayer in public schools, and abolishing abortion. Toward the end of the debate, Keyes stated he could not support Giuliani if he were to win the nomination due to the former New York mayor's position on abortion.

In the Iowa caucuses, Keyes did not appear on any of the election totals. Keyes stated that many of the caucus locations he visited did not list him as a choice. His campaign CEO, Stephen Stone blamed much of this on the media and on Keyes's decision to enter the race late. Stone explained that the media would not acknowledge Keyes's candidacy, making it difficult to run an effective campaign.

Keyes supports an amendment to the Constitution barring same-sex marriage. He stated he would not have gone to war in Iraq, but also said that the war was justified and defended President George W. Bush's decision in one of his 2004 debates. Keyes has stated that troops should stay in Iraq, but also said that he would have turned over operations to the United Nations. However, Keyes has also stated that even while he was an ambassador there he was not a supporter of the United Nations.

After the early states, Keyes exclusively campaigned in Texas, where he finished with 0.60 percent of all votes cast. Keyes received numerous monetary contributions during his 2008 campaign, including a donation of $4000 from a key supporter Stephanie Tufenkjian, an important political advocate.

Following Texas, the Keyes campaign moved to seeking the Constitution Party nomination, but he continued to appear on several Republican ballots. On May 6, Keyes scored his best showing of the campaign by winning 2.7% for fourth place in North Carolina, earning him two delegates to the Republican National Convention.

Departure from Republican Party

Keyes first stated that he was considering leaving the Republican Party during a January 2008 appearance on The Weekly Filibuster radio show. He did not withdraw his candidacy after John McCain won the necessary 1,191 delegates to the Republican National Convention, even though he was no longer campaigning for the Republican nomination. On March 27, 2008, Keyes's campaign website began displaying the Constitution Party's logo, along with a parody of the trademarked GOP logo in the form of a dead elephant. This appeared to be an indication of Keyes's intentions to quit the Republican party and to begin officially seeking the Constitution Party's presidential nomination.

On April 15, Keyes confirmed his split from the Republican Party and his intention to explore the candidacy of the Constitution Party. He lost his bid for the party's nomination, however, coming in second to 2004 CP vice presidential candidate Chuck Baldwin at the party's national convention in Kansas City, Missouri on April 26, 2008. During the convention, the party's founder, Howard Phillips, gave a controversial speech in which he referred to Keyes as "the Neocon candidate" who "lingered in the Republican Party until a week ago." Following the defeat, Keyes held an interview with Mike Ferguson in which he compared his defeat to an abortion. Later, Keyes told a group of his supporters that he was "prayerfully considering" making a continued bid for the presidency as an independent candidate, and asserted his refusal to endorse Baldwin's candidacy.

Instead, Keyes formed a new third party, America's Independent Party, for his presidential candidacy. America's Independent Party gained the affiliation of a faction of California's American Independent Party. However, the AIP ticket, which had Brian Rohrbough of Colorado as its vice presidential candidate, was only on the ballot in California, Colorado, and Florida.

In the federal election held on November 4, 2008, Keyes received 47,694 votes nationally to finish seventh. About 86% (40,673) of the votes he received were cast in California.

Obama citizenship lawsuit

Keyes filed a lawsuit on November 14, 2008 against the California Secretary of State, then-President-elect Barack Obama, then-Vice President-elect Joe Biden, and California's 55 Democratic electors, seeking to challenge Obama's eligibility for the US Presidency. The suit requests that Obama provide documentation that he is a natural born citizen of the United States.

Following Obama's inauguration, Keyes denied he had been constitutionally inaugurated, refused to call him president, and called him an "usurper" and a "radical communist".

Keyes has worked as a media commentator and talk show personality. In 1994, he began hosting a syndicated radio show called The Alan Keyes Show: America's Wake-Up Call from Arlington, Virginia. The show became simulcast on cable's National Empowerment Television in 1997. Keyes also launched various web-based organizations ... notably Renew America and the Declaration Foundation, both headquartered in Washington, D.C.

In 2002, he hosted a live television commentary show, Alan Keyes Is Making Sense, on the MSNBC cable news channel. The network canceled the show in July, citing poor ratings. The cancellation triggered a currently ongoing boycott led by Jewish activism website Mesora.org that numbers more than 72,000 members. The show was unsympathetic to supporters of the al-Aqsa Intifadah — whom Keyes frequently debated on the program — and supported the Israeli crackdown on Palestinians. The show also featured critical discussion of homosexuality and of priests accused in the Roman Catholic Church sex abuse scandals. The last episode was broadcast on June 27, 2002. As a result of Keyes's strong advocacy of Israel on his MSNBC show, in July 2002 the state of Israel awarded him a special honor "in appreciation of his journalistic endeavors and his integrity in reporting" and flew him in to meet Prime Minister Ariel Sharon.

In August 2003, Keyes came out in defense of Alabama Chief Justice Roy Moore, citing both the U.S. Constitution and the Alabama constitution as sanctioning Moore's (and Alabama's) authority to publicly display the Ten Commandments in the state's judicial building, in defiance of a court order from U.S. District Judge Myron Thompson. Although the monument was ultimately removed by state authorities, the issue impelled Keyes to spend the next year advocating his understanding of the Constitution's protection of the right of states to display monuments that reflect the religious sentiments of the people in their states. As a result, he published an essay describing his rationale titled "On the establishment of religion: What the Constitution really says."

In early 2005, Keyes sought to intervene in the Terri Schiavo case, arguing that Schiavo's life was protected by the Florida constitution, and that Governor Jeb Bush had final authority to determine the outcome of the case under state provisions. He attempted to meet with Bush to discuss the provisions of Florida law that authorized the governor to order Schiavo's feeding tubes reinserted — something Bush claimed he wished to do, but for which he said he lacked authority — but the governor declined to meet with Keyes. Keyes subsequently wrote an essay directed openly at Governor Bush titled "Judicial review and executive responsibility", days after Schiavo's feeding tube had been removed.

In November 2006, Keyes criticized Massachusetts governor Mitt Romney for instituting gay marriage entirely on his own — according to Keyes — with no requirement or authority to do so under Massachusetts law. Keyes said Romney's actions, which he suggested were due to a complete misunderstanding of his role as governor and of the limitations of the judicial branch of government, were not necessitated by a ruling of the Massachusetts Supreme Judicial Court in November 2003 that directed the state legislature to institute same-sex marriage. The Massachusetts Supreme Judicial court had ruled that the state law banning same-sex marriage was not constitutional. The court gave the Massachusetts Legislature 180 days to modify the law; after it failed to do so, Gov. Mitt Romney ordered town clerks to begin issuing marriage licenses on May 17, 2004, in compliance with the court ruling.

Commenting on the issue, Keyes asked rhetorically, "Since the legislature has not acted on the subject, you might be wondering how it is that homosexuals are being married in Massachusetts. It's because Mitt Romney, who is telling people he's an opponent of same-sex marriage, forced the justices of the peace and others to perform same-sex marriage, all on his own, with no authorization or requirement from the court. Tells you how twisted our politicians have become."

In December 2009, Keyes authored a column for the World Net Daily critical of evolution and in support of Intelligent Design.

Keyes serves on the board of advisors for the Catholic League, a non-profit, Roman Catholic advocacy group headed by William A. Donohue. He is also on the advisory boards of Eagle Forum, the American Life League, Survivors of the Abortion Holocaust, and the American Coalition of Life Activists. He is involved in the promotion of the Constitution Party's Save America Summit, the Christian Exodus separatist movement, and evangelists Wiley Drake and Flip Benham.

Keyes also made a widely discussed appearance in the 2006 film Borat.