2009–10 United States network television schedule (late night)

These are the late night schedules for the four United States broadcast networks that offer programming during this time period, from September 2009 to August 2010.

Affiliates will fill non-network schedule with local, syndicated, or paid programming.

Affiliates also have the option to preempt or delay network programming at their discretion.

Note: As the result of the Tonight Show conflict, O'Brien was let go at NBC, with his version of The Tonight Show ending on January 22, 2010.

O'Brien returned to late night in the Fall of 2010, with Conan airing on TBS.