WJXT originally signed on the air on September 15, 1949, as WMBR-TV, the second television station to sign on in the state of Florida and a primary CBS affiliate on VHF channel 4 after WTVJ (also on channel 4, now an NBCowned-and-operated station on channel 6) in Miami–Fort Lauderdale. The Washington Post Company acquired the WMBR stations in 1953.
The Washington Post Company sold WMBR-AM-FM in 1958, while it kept the television station, whose callsign it changed to the current WJXT.
During negotiations between Post-Newsweek Stations and CBS on a new affiliation agreement in early 2002, CBS supplied Post-Newsweek with a list of demands that would have resulted in WJXT no longer receiving monetary compensation for the carriage of the network's programming (CBS was moving toward a reverse compensation model for its affiliates during this time) and would have required the station to run the entire CBS network schedule in pattern without preemptions, except for extended local breaking news and severe weather coverage. Station and Post-Newsweek company management believed these stipulations would come at the expense of local programming. Rather than give in to the network's demands, Post-Newsweek Stations announced on April 3, 2002 that it would not renew channel 4's affiliation agreement with CBS, which was set to expire on July 10. UPN affiliate WTEV-TV (UHF channel 47, now WJAX-TV)—at that time owned by Clear Channel Communications—subsequently signed an agreement with CBS to become the network's new Jacksonville affiliate two weeks after WJXT's disaffiliation announcement on April 23, 2002. The affiliation switch became official at 5 am, on July 15, 2002, ending WJXT's 53-year association with CBS. This also triggered an affiliation switch in Gainesville where WGFL became a CBS affiliate; that station was a primary affiliate of The WB at the time.
Variant used from 2002 to 2005, using former longtime slogan The One and Only Channel 4; the slogan was used beginning in 1991.
Variant used from 2005 to 2014, featuring current slogan.
Glossier variant, alternately used from 2005 to 2014.