KTVI (channel 2) is a television station in St. Louis, Missouri, United States, affiliated with the Fox network. It is owned by Nexstar Media Group alongside KPLR-TV (channel 11), an owned-and-operated station of The CW. The two stations share studios on Ball Drive in Maryland Heights; KTVI's transmitter is located in Sappington, Missouri.

The station first signed on the air by Signal Hill Telecasting Corporation on August 10, 1953, as WTVI, broadcasting on UHF channel 54. It was originally licensed to Belleville, Illinois (across the Mississippi River from St. Louis), and was the second television station in the St. Louis market after KSD-TV (channel 5, now KSDK) on February 8, 1947. The station's first broadcast was a baseball game between the St. Louis Browns and Cincinnati Reds, announced by Buddy Blattner, Bill Durney and Milo Hamilton. It operated as a primary CBS affiliate, and held secondary affiliations with ABC and DuMont. DuMont affiliation was agreed to in February 1953 to replace KSD-TV. The station was project to sign on May 15, 1953. The station originally operated from studios located in Alton, Illinois. The CBS affiliation moved to KWK-TV (channel 4, now KMOV) when it debuted on July 8, 1954; more or less by default, WTVI became a primary ABC affiliate.

The station moved to UHF channel 36, and relocated its city of license to St. Louis on April 9, 1955, keeping the base "TVI" letters as part of its callsign while flipping the first assigned letter from "W" to "K" with this switch of sides of the Mississippi River, thus changing to the current KTVI. It moved its operations to facilities located in the Clayton-Tamm/Dogtown neighborhood in west St. Louis (off present-day I-64/US 40 at the intersection of Berthold, Oakland, and Hampton Avenues). However, the Federal Communications Commission (FCC) had recently changed its regulations so that the station could have kept its license in Belleville even while moving its main studio to St. Louis. The WTVI calls are currently used by a PBS member station in Charlotte, North Carolina.

The station lost DuMont programming when the network ceased operations in 1956, making KTVI an exclusive ABC affiliate. As the FCC would not require television sets to include UHF tuners until 1961, on April 15, 1957, KTVI moved to VHF channel 2, something it had attempted to do soon after moving to St. Louis–the channel 2 allocation had been reassigned from Springfield, Illinois, under pressure from the Truman administration, originally done so as not to interfere with CBS-owned WBBM-TV in Chicago.

For many years, the station was owned by the Newhouse newspaper chain (now Advance Publications), owners of the now-defunct St. Louis Globe-Democrat. In 1980, Newhouse exited from broadcasting, and sold KTVI and its other television outlets to the Los Angeles-based Times Mirror Company. In March 1993, in order for the company to concentrate on its newspaper and cable television system franchises, Times Mirror sold KTVI and its three sister stations—fellow CBS affiliates KTBC in Austin and KDFW-TV in Dallas–Fort Worth and NBC affiliate WVTM-TV in Birmingham—to Argyle Television Holdings in a two-part deal for $335 million in cash and securities. Under the transaction's purchase option structure, WVTM and KTVI were the first two stations that Argyle sold to New World, which the latter purchased for a combined $80 million. (It would later respectively acquire KDFW and KTBC from the group for $335 million in cash and securities). The purchase of the entire group was completed in December of that year following securement of financing for the deal.

On May 23, 1994, as part of a $500-million overall deal in which network parent News Corporation also purchased a 20% equity interest in the group, New World signed a long-term affiliation agreement with Fox to switch twelve television stations—five that New World had already owned and seven that the company was in the process of acquiring through separate deals with Great American Communications and Argyle Television Holdings (which New World purchased one week later in a purchase option-structured deal for $717 million), including KTVI—to the network. The stations involved in the agreement—all of which were affiliated with one of the three major broadcast networks (CBS, ABC and NBC)—would become Fox affiliates once individual affiliation contracts with each of the stations' existing network partners had expired. (WVTM did not switch as WBRC, which was placed in a blind trust, was later sold to Fox outright as New World could not keep both due to FCC rules at the time that forbade duopolies). The deal was motivated by the National Football League (NFL)'s awarding of the rights to the National Football Conference (NFC) television package to Fox on December 18, 1993, in which the conference's broadcast television rights moved to the network effective with the 1994 NFL season, ending a 38-year relationship with CBS.

ABC had a fourteen-month leeway to find a new affiliate in St. Louis, as its contract with KTVI did not expire until July 1, 1995; its affiliation contracts expired only one month after as CBS's agreement with KDFW and KTBC was scheduled to expire, giving the networks that were already affiliated with the three former Argyle stations slated to switch to Fox a longer grace period to find new affiliates than CBS, NBC and/or ABC were given in most of the other markets affected by the Fox-New World deal (ABC's affiliation contracts with WGHP and WBRC ended even later, respectively expiring in September 1995 and September 1996). Of ABC's options, four prospects were automatically eliminated: KSDK was in the middle of a long-term affiliation agreement between its owner at the time, Multimedia Broadcasting, and NBC; KMOV was under a long-term agreement between CBS and Paramount Stations Group (which was in the process of selling KMOV and its four other major network affiliates to focus on its Fox-affiliated and independent stations that were set to become charter affiliates of group parent Viacom's then-upstart United Paramount Network [UPN]); and KNLC (channel 24, now a MeTV owned-and-operated station) and WHSL (channel 46, now Ion Television O&O WRBU) were respectively owned by the locally based New Life Christian Church and the Home Shopping Network at the time, and both stations had inferior signals, even on cable, making either unlikely choices as even last-ditch options. This left independent station KPLR-TV (channel 11, now a CW owned-and-operated station) and existing Fox station KDNL-TV (channel 30) as the only viable options with which ABC could reach an affiliation agreement. The network first approached KPLR about negotiating an affiliation deal, ultimately to be turned down by its then-owner Koplar Communications. On August 25, 1994, River City Broadcasting reached an agreement with ABC to shift the network's affiliation rights to KDNL.

KTVI switched to Fox on August 7, 1995, ending its relationship with ABC after 42 years; concurrently, ABC programming moved to KDNL-TV. The last ABC program to air on KTVI was an ABC Sunday Night Movie presentation of Survive the Savage Sea at 8 p.m. Central Time on August 6.^{[citation needed]} As with most of the other New World-owned stations affected by the agreement with Fox, KTVI retained its longtime "Channel 2" branding upon the affiliation switch, with references to the Fox logo and name limited in most on-air imaging; it also retained the news branding it had been using before it joined the network—in its case, The 2 News Team, which the station adopted in November 1990 as an ABC affiliate. In addition to expanding its local news programming at the time it joined Fox, the station replaced ABC daytime and late-night programs that migrated to KDNL with an expanded slate of syndicated talk shows as well as some documentary-based reality series and off-network sitcoms, and also acquired some syndicated film packages and first-run and off-network syndicated drama series for broadcast in weekend afternoon timeslots on weeks when Fox did not provide sports programming.