1999–2000 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 1999 to August 2000.

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.

Returning series New series Not returning from 1998-99: