The 1988–89 network television schedule for the four major English language commercial broadcast networks in the United States covers primetime hours from September 1988 through August 1989. The schedule is followed by a list per network of returning series, new series, and series cancelled after the 1987–88 season.

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 Time 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]

The 1988 Writers Guild of America strike lasted between March 7 and August 7. During the strike, production on scripted television series across all of the major television networks was suspended. The writers' strike forced the networks to postpone the start of the fall 1988 schedule later than usual; rather than the traditional late-September/early-October start, new and returning series had their premieres delayed until late October and into November. In the interim, the networks had to rely on a hodgepodge of programming, including reruns, films, entertainment and news specials, program-length political advertising, and unscripted original series (e.g. CBS' High Risk); NBC and ABC also benefited from sports programming (NBC relied on the Summer Olympics in September and the World Series in October, while ABC had postseason baseball coverage and moved up the start time for the early weeks of Monday Night Football from 9 p.m. ET to 8 p.m. ET to replace MacGyver, which was not yet ready with new episodes at the time). Even though previous strikes of Hollywood employees occurred in 1980 and 1981, those strikes only had a minor effect on the production of television programs that aired in the 1980–81 and 1981–82 seasons. The 1988–89 television season was thus the first of three television seasons to have its start delayed due to issues outside of the control of the major networks; the next two instances occurred in the 2001–02 season (due to the networks' news coverage of the September 11 attacks) and the 2020–21 season (due to the suspension of television productions as a result of the COVID-19 pandemic).

Notes:

• Quantum Leap had a two-hour premiere Sunday, March 26, 1989, on NBC.
• The Jim Henson Hour briefly replaced The Magical World of Disney on May 14, 1989, and again between July 9-July 30.
• On ABC, A Fine Romance was supposed to air 8-9 p.m., but production delays amidst the strike forced the move to Thursdays.^[2]

(*) B.L. Stryker, Columbo, Gideon Oliver

Note: On CBS, Frank's Place consisted of reruns of the 1987-88 sitcom. On ABC, ABC Saturday Mystery Movie was supposed to air 9-11 p.m., but production delays amidst the strike force the move to Mondays.^[2]