1989–90 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 1989 to August 1990. 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.

Legend
Light blue indicates Local programming.

Gray indicates encore programming.

Yellow indicates late night talk or variety shows.

Gold indicates network news programming.

Monday-Friday
The Pat Sajak Show was reduced to 60 minutes on October 30, 1989.

ABC
Returning series
 * Nightline

New series
 * Into the Night Starring Rick Dees

CBS
Returning series
 * CBS Late Night
 * CBS News Nightwatch
 * The Pat Sajak Show

NBC
Returning series
 * Friday Night Videos
 * The George Michael Sports Machine
 * Late Night with David Letterman
 * Later With Bob Costas
 * Saturday Night Live
 * The Tonight Show Starring Johnny Carson

Fox
Returning series
 * Comic Strip Live