The 1989–90 network television schedule for the four major English language commercial broadcast networks in the United States covers primetime hours from September 1989 through August 1990. The schedule is followed by a list per network of returning series, new series, and series cancelled after the 1988–89 season.

Beginning this season, Fox started their prime time expansion starting with Mondays.

This is the first season to feature entirely closed captioning programs on the Big Four networks.

This was the first time that two programs were tied for the no. 1 spot in the Nielsen ratings.

PBS is not included; member stations have local flexibility over most of their schedules and broadcast times for network shows may vary.

New series are highlighted in bold.

All times are U.S. Eastern and Pacific Time (except for some live sports or events). Subtract one hour for Central, Mountain, Alaska and Hawaii-Aleutian times.

Each of the 30 highest-rated shows is listed with its rank and rating as determined by Nielsen Media Research.^[1]

Note: In Living Color premiered Sunday April 15 at 9:30 PM on Fox.

Notes: Seinfeld premiered July 5, 1989 at 9:30 p.m. on NBC. FM aired at 9:30 p.m. on NBC from August 23 to September 6, 1989. Glory Days aired at 8:00 p.m. on Fox from July 25 to August 2, 1990. Molloy aired at 9:00 p.m. on Fox from July 25 until August 15, 1990. Fox aired movies at 8:00 p.m. on an irregular basis.

Notes: The Eddie Capra Mysteries, which CBS aired from July 26 to August 30, consisted of reruns of episodes from the 1978-79 NBC series. FM premiered August 17, 1989 at 9:30 p.m. on NBC and aired its fifth episode on September 14.

Note: Comic Strip Live aired at 11:00 p.m.-12:00 a.m. on Fox.