It is owned and operated by network majority owner Nexstar Media Group alongside Fox affiliate KTVI (channel 2).

[2] The station's call letters were derived from the name of its founding owner, St. Louis real estate developer and hotelier Harold Koplar.

CBS was originally granted a construction permit by the Federal Communications Commission (FCC) to build channel 11 in January 1957, prevailing over three other locally based competitors.

[5] Almost immediately, the three-way deal was held up after the St. Louis Amusement Company, one of the original applicants for channel 11, protested to the United States Court of Appeals in January 1958.

"Ted" Koplar began working behind the scenes at KPLR, producing sports programming and developing the station's first regular local newscast.

Ted Koplar became president and chief executive officer of channel 11 in 1979, and gained complete control of the station upon his father's death in 1985.

For most of its existence, KPLR was a traditional independent station featuring cartoons, sitcoms, movies, drama series and locally produced newscasts.

KTVI was among the thirteen "Big Three" network-affiliated television stations already owned or in the process of being acquired by New World Communications (and one of three out of the four stations that the group was acquiring from Argyle Television Holdings at the time) that were slated to switch to Fox under a long-term affiliation agreement announced between New World and then-Fox network parent News Corporation on May 23, 1994.

The sale was finalized on March 1, 1998, ending 38 years of local, family ownership and earning a handsome return on their original investment.

As part of the sale agreement, Ted Koplar signed a three-year contract to remain with KPLR-TV as the station's CEO, along with serving as a consultant to ACME, for an annual salary of $1 million.

On December 30, 2002, Tribune Broadcasting announced it would purchase KPLR-TV and sister station KWBP in Portland, Oregon, from ACME Communications for $275 million; the sale was finalized on March 21, 2003.

[27][28][29] Nearly one month after the CW launch announcement, on February 22, 2006, News Corporation subsidiaries Fox Television Stations and Twentieth Television announced the launch of MyNetworkTV, a network created primarily to serve as a network programming option for UPN and WB stations that were left out of The CW's affiliation deals.

Although KTVI was the senior partner in the deal, it vacated its longtime studios in the Clayton-Tamm/Dogtown neighborhood on St. Louis' west side and moved its operations to KPLR's Maryland Heights facility.

[38][39] Prohibited from owning all three stations, Sinclair would have been required to sell KPLR to a third party to comply with ownership rules and alleviate potential antitrust issues.

For example, a 2021 college football matchup between Illinois and Nebraska was moved to KPLR due to KTVI's obligation to air Green Bay Packers preseason games.

During its WB years, KPLR-TV also syndicated its coverage of the Cardinals games to other stations in Arkansas, Iowa, Indiana, Kentucky, Missouri, Oklahoma, and Tennessee.

The show featured the most famous wrestlers in the National Wrestling Alliance, which was controlled in part by St. Louis promoter Sam Muchnick.

Participants included Ric Flair, Harley Race, former NFL player Dick the Bruiser and Ted DiBiase, and is considered one of the wrestling industry's most historic programs.

About 1,100 episodes were produced during the show's run, which ended on September 10, 1983, when Muchnick retired from promoting and handed the slot over to the World Wrestling Federation.

It was originally broadcast from The Casino Queen's Club Sevens for the first 20 months of its run, before the program relocated to AJ's Bar and Grill in December 2007.

From 1959 to 1968, KPLR aired the after-school children's program Captain 11's Showboat, which introduced The Three Stooges to St. Louis area television viewers.

This was most notably achieved through World Events Productions, which distributed three animated series Voltron: Defender of the Universe, Saber Rider and the Star Sheriffs, and Denver, the Last Dinosaur.

In the past, KPLR has attempted to format its newscasts to attract a younger audience, employing anchors under the age of 35 and featuring a more fast-paced reporting style.

In February 2021, both stations overhauled their set again with an expansion of the physical studio space with multiple venues and a larger video wall.