2003–04 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 2003 to August 2004.

All times are Eastern or Pacific.

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: Craig Kilborn left The Late Late Show at the end of August 2004, with guest hosts taking his place until Craig Ferguson was selected as the permanent host.