1998–99 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 1998 to August 1999. 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
Note: NBC Nightside was cancelled in September 1998

ABC
Returning series
 * ABC World News Now
 * ABC World News This Morning
 * Nightline
 * Politically Incorrect with Bill Maher

Not returning from 1997-98:
 * ABC in Concert

CBS
Returning series
 * CBS Morning News
 * Late Show with David Letterman
 * The Late Late Show with Tom Snyder
 * Up to the Minute

New series
 * The Late Late Show with Craig Kilborn

Fox
Returning series
 * MADtv

NBC
Returning series
 * Friday Night
 * Late Night with Conan O'Brien
 * Later
 * NBC News at Sunrise
 * Saturday Night Live
 * The Tonight Show with Jay Leno

Not returning from 1997-98:
 * NBC Nightside