Chait, a doctor's son, grew up in the suburbs of Detroit and is a graduate of the University of Michigan. There he wrote for The Michigan Daily and co-founded "The Michigan Independent". He lives in Washington DC and is married to Robin Chait, an education-policy analyst at the liberal Center for American Progress think tank.

Chait began working at The New Republic in 1995. In January 2010, The New Republic replaced The Plank, TNR's group blog, with the Jonathan Chait Blog. His writing has also appeared in The New York Times, The Wall Street Journal, Slate and Reason. He took over The New Republic's TRB column from Peter Beinart in March 2007. His columns from 2008 are a finalist for the National Magazine Award, in the category of best commentary.

On Sept. 12, 2007, his book, THE BIG CON: The true story of how Washington got hoodwinked and hijacked by crackpot economics, was published by Houghton-Mifflin.

On March 16, 2009, Chait appeared on Comedy Central's The Colbert Report to refute conservative arguments that the New Deal was a failure. The impetus for that appearance was an article he wrote for The New Republic called "Wasting Away in Hooverville."

Chait also appears in "The Rivalry," a 2007 HBO documentary about the history and culture of the Michigan-Ohio State football rivalry.

Chait usually writes about domestic politics and policy. Many of his writings are critiques of what he perceives to be illogical positions taken by conservatives. A self-described liberal hawk, he has however written pieces critical of left-wing figures such as Naomi Klein, and also wrote a TNR cover article condemning the state of Delaware. He makes frequent use of humor and sarcasm.

He drew considerable attention with his "Case for Bush Hatred", in which he defended his dislike not only of Bush's policies but also his personality and mannerisms.

Chait took a dim view of the presidential candidacies of Howard Dean, John Kerry and Hillary Clinton, believing that all of them suffered problems with electability. During the 2008 presidential race, Chait wrote many items supportive of Barack Obama

Chait strongly criticized the editorial staff of the Detroit Free Press following a controversial article by Michael Rosenberg that alleged systemic infractions of NCAA Rules by the Michigan football team. Chait suggested Rosenberg's editor should "lose his job" and called the investigation's methodology "journalistic malpractice." On February 22, 2010, following an investigation stemming from allegations raised in Rosenberg's article, UM announced that the NCAA has found probable cause that the school committed five major violations, corroborating some but not all of the allegations in Rosenberg's article. On Tuesday, May 25, 2010 the University of Michigan responded to the NCAA Notice of Allegations ; after which, Chait claimed that Rosenberg's allegations that coach Rich Rodriguez "operated a football sweatshop has been totally debunked."