The following is the 1998–99 network television schedule for the six major English language commercial broadcast networks in the United States. The schedule covers primetime hours from September 1998 through August 1999. The schedule is followed by a list per network of returning series, new series, and series cancelled after the 1997–98 season. All times are Eastern and Pacific, with certain exceptions, such as Monday Night Football. New series highlighted in bold. Each of the 30 highest-rated shows is listed with its rank and rating as determined by Nielsen Media Research. Other Legend PBS, the Public Broadcasting Service, is not included; member stations have local flexibility over most of their schedules and broadcast times for network shows may vary. Also not included is Pax TV (now Ion), a venture of Paxson Communications (now Ion Media) that debuted on August 31, 1998; although Pax carried a limited schedule of first-run programs in its early years, its schedule otherwise was composed mainly of syndicated reruns.

Sunday

Monday

Note: UPN only broadcast the first two episodes of Power Play. On August 16, 1999, ABC aired the series episode of Who Wants to Be a Millionaire at 8:30pm EDT. It was the only 30 minute episode to air on a Monday night.

Tuesday

NOTE: On Fox, Brimstone was supposed to premiere 9-10, but it was moved up to Friday.

Wednesday

Thursday

Note: On Fox, Hollyweird was supposed to premiere 9:00-10:00 but it was canceled due to a conflict with Shaun Cassidy.

Friday

Note: On Fox, the one-hour drama Brimstone premiered at 8:00 on October 23, 1998.

Saturday

By network

ABC

Not returning from 1997–98:

CBS

Not returning from 1997–98:

Fox

New series Not returning from 1997–98:

NBC

Not returning from 1997–98:

UPN

Not returning from 1997–98:

The WB

Not returning from 1997–98: Note: The * indicates that the program was introduced in midseason.