The Tonight Show with Conan O'Brien is an American late-night talk show that featured Conan O'Brien as host from June 1, 2009 to January 22, 2010 as part of NBC's long-running Tonight Show franchise. The program's host, Conan O'Brien, previously hosted NBC's Late Night with Conan O'Brien, which followed The Tonight Show with Jay Leno for 16 years, until O'Brien's brief succession over Leno.

Many members of the Late Night cast and crew made the transition to The Tonight Show. The Max Weinberg 7, the house band from O'Brien's Late Night, served as the house band under the new name, Max Weinberg and The Tonight Show Band. Andy Richter returned to the show as announcer, and also began resuming his role as sidekick, shortly before the show's conclusion. The opening and closing theme song from Late Night was also carried over to Tonight, in a slightly altered form.

In January 2010, after the show had been on the air for seven months, it was announced that NBC was intending to move Jay Leno from primetime back to his original timeslot at 11:35 pm, with O'Brien's show starting shortly after midnight. In response to the announcement, O'Brien released a press statement saying that he would not continue as host of The Tonight Show if it was moved to any time after midnight to accommodate The Jay Leno Show. He feared it would ruin the long and rich tradition of The Tonight Show. It had been on after the late local newscasts from the beginning. After two weeks of negotiations, NBC announced that they had paid $45 million to buy out O'Brien's contract, ending both his tenure as host as well as his relationship with NBC after 22 years.