Alinsky was born in Chicago, Illinois in 1909 to Russian Jewish immigrant parents, the only surviving son of Benjamin Alinsky's marriage to his second wife, Sarah Tannenbaum Alinsky. Alinsky stated during an interview that his parents never became involved in the "new socialist movement." He added that they were "strict orthodox, their whole life revolved around work and synagogue ... I remember as a kid being told how important it was to study."

Because of his strict Jewish upbringing, he was asked whether he ever encountered anti-semitism while growing up in Chicago. He replied, "it was so pervasive you didn't really even think about it; you just accepted it as a fact of life." He considered himself to be a devout Jew until the age of 12, after which time he began to fear that his parents would force him to become a rabbi. "I went through some pretty rapid withdrawal symptoms and kicked the habit ... But I'll tell you one thing about religious identity," he added. "Whenever anyone asks me my religion, I always say...and always will say... Jewish."

Education

He worked his way through the University of Chicago, where he majored in archaeology, a subject that fascinated him. His plans to become a professional archaeologist were changed due to the ongoing economic Depression. He later stated, "Archaeologists were in about as much demand as horses and buggies. All the guys who funded the field trips were being scraped off Wall Street sidewalks."

Early jobs

After attending two years of graduate school he dropped out to accept work with the state of Illinois as a criminologist. On a part-time basis, he also began working as an organizer with the Congress of Industrial Organizations (C.I.O.). After a few years, by 1939, he became less active in the labor movement and became more active in general community organizing, starting with the slums of Chicago. His early efforts to "turn scattered, voiceless discontent into a united protest aroused the admiration of Illinois governor Adlai Stevenson, who said Alinsky's aims 'most faithfully reflect our ideals of brotherhood, tolerance, charity and dignity of the individual.' "

As a result of his efforts and success at helping slum communities, he spent the next 10 years repeating his organization work across the nation, "from Kansas City and Detroit to the barrios of Southern California." By 1950 he turned his attention to the African-American ghettos of Chicago, where his actions quickly earned him the hatred of Mayor Richard J. Daley, although Daley would later say that "Alinsky loves Chicago the same as I do." He traveled to California at the request of the Bay Area Presbyterian Churches to help organize the black ghetto in Oakland. Hearing of his plans, "the panic-stricken Oakland City Council promptly introduced a resolution banning him from the city."

In the 1930s, Alinsky organized the Back of the Yards neighborhood in Chicago (made infamous by Upton Sinclair's novel The Jungle for the horrific working conditions in the Union Stock Yards). He went on to found the Industrial Areas Foundation while organizing the Woodlawn neighborhood, which trained organizers and assisted in the founding of community organizations around the country. In Rules for Radicals (his final work, published in 1971 one year before his death), he addressed the 1960s generation of radicals, outlining his views on organizing for mass power. In the first chapter, opening paragraph of the book Alinsky writes, "What follows is for those who want to change the world from what it is to what they believe it should be. The Prince was written by Machiavelli for the Haves on how to hold power. Rules for Radicals is written for the Have-Nots on how to take it away."Alinsky did not join political organizations. When asked during an interview whether he ever considered becoming a Communist party member, he replied:

"Not at any time. I've never joined any organization...not even the ones I've organized myself. I prize my own independence too much. And philosophically, I could never accept any rigid dogma or ideology, whether it's Christianity or Marxism. One of the most important things in life is what Judge Learned Hand described as 'that ever-gnawing inner doubt as to whether you're right.' If you don't have that, if you think you've got an inside track to absolute truth, you become doctrinaire, humorless and intellectually constipated. The greatest crimes in history have been perpetrated by such religious and political and racial fanatics, from the persecutions of the Inquisition on down to Communist purges and Nazi genocide."

Nor did he have much respect for mainstream political leaders who tried to interfere with growing black-white unity during the difficult years of the Great Depression. In Alinsky's opinion, new voices and new values were being heard in the U.S., and "people began citing John Donne's 'No man is an island,'" he said. He observed that the hardship affecting all classes of the population was causing them to start "banding together to improve their lives," and discovering how much in common they really had with their fellow man. He stated during an interview a few of the causes for his active organizing in black communities:

"Negroes were being lynched regularly in the South as the first stirrings of black opposition began to be felt, and many of the white civil rights organizers and labor agitators who had started to work with them were tarred and feathered, castrated...or killed. Most Southern politicians were members of the Ku Klux Klan and had no compunction about boasting of it."

Alinsky described his plans in 1972 to begin to organize the White middle class across America, and the necessity of that project. He believed that what President Richard Nixon and Vice-President Spiro Agnew called "The Silent Majority" was living in frustration and despair, worried about their future, and ripe for a turn to radical social change, to become politically-active citizens. He feared the middle class could be driven to a right-wing viewpoint, "making them ripe for the plucking by some guy on horseback promising a return to the vanished verities of yesterday." His stated motive: "I love this goddamn country, and we're going to take it back."

The documentary The Democratic Promise: Saul Alinsky and His Legacy, states that "Alinsky championed new ways to organize the poor and powerless that created a backyard revolution in cities across America." Alinsky formed the Industrial Areas Foundation in 1940, and Chambers became its Executive Director after Alinsky died. Since the IAF's formation, hundreds of professional community and labor organizers and thousands of community and labor leaders have attended its workshops. Fred Ross, who worked for Alinsky, was the principal mentor for Cesar Chavez and Dolores Huerta. Hillary Clinton's senior honors thesis on Saul Alinsky, written at Wellesley College, noted that Alinsky's personal efforts were a large part of his method.

Several prominent national leaders have been influenced by Alinsky's teachings, including Barack Obama, Ed Chambers, Tom Gaudette, Ernesto Cortes, Michael Gecan, Wade Rathke, and Patrick Crowley. Alinsky's techniques were quoted in a memo for Tea Party activists seeking to disrupt congressional town halls on August, 2009.

Alinsky is often credited with laying the foundation for the grassroots political organizing that dominated the 1960s. Jack Newfield writing in New York Magazine included Alinsky among "the purest avatar of the populist movement," along with Ralph Nader, Cesar Chavez, and Jesse Jackson.

In 1969, he was awarded the Pacem in Terris Peace and Freedom Award.

Alinsky died of a heart attack at the age of 63 in 1972, in Carmel, California.