The redheaded comedian was born April 18, 1963, in Brookline, Massachusetts. He's equally smart as he is funny -- O'Brien attended Harvard University, where he was elected twice as president of the school's parody magazine, The Harvard Lampoon.
After college, O'Brien moved to Los Angeles to work on Not Necessarily the News, a cable series on HBO. He also performed with famed improv group, The Groundlings, while he honed his craft. It paid off when he began writing for Saturday Night Live in 1988 (the show's writing staff won an Emmy in 1989). In 1992, when Jay Leno and David Letterman were both vying for Johnny Carson's job as host of The Tonight Show, NBC chose O'Brien as host of Late Night after Letterman left for CBS. He struggled in the ratings at first, but after four years on air, NBC offered him a five-year contract.
In 2000, O'Brien met avertising executive Liza Powell. The two married on January 12, 2002, in Seattle and have two children.
In December 2008, NBC announced a shift in its late night lineup. When Leno moved to a new 10 p.m. timeslot, O'Brien would replace him as host of The Tonight Show and Saturday Night Live alum Jimmy Fallon would take over Late Night. The move was short-lived, because the network announced more changes in January 2010: Leno would return to the 11:35 p.m. timeslot after the Winter Olympics in February. The fates of The Jay Leno Show, The Tonight Show with Conan O'Brien and Late Night with Jimmy Fallon were up in the air, causing very public disputes among the comics and the network. On January 21, 2010, NBC officially anounced O'Brien's last day of hosting would be January 22, and he would receive $33 million for his early exit, with an additional $12 million going to his employees.
In April 2010 he announced his return to latnight TV. His new show on TBS will go head-to-head against Leno and Letterman in the 11 p.m. timeslot starting in November.