OETA traces its history to 1953, when the Oklahoma Legislature created it via statute. It was charged with providing educational television programming to Oklahomans on a coordinated statewide basis, made possible with cooperation from the state's educational, government and cultural agencies. After securing a license from the Federal Communications Commission and funding from various special interest groups, Oklahoma City's KETA was finally able to sign on the air as the nation's 11th educational television station (and the first non-commercial station in Oklahoma) on April 13, 1956. It was originally a member station of National Educational Television, until NET was replaced by the Public Broadcasting Service in 1970, taking over many of the functions of its predecessor.

Three more stations signed on the course of 19 years (with a statewide network of translators also being built during this timeframe), extending OETA's programming to portions of Kansas, Missouri, Arkansas and Texas. A satellite station of KETA in Tulsa, KOED-TV (channel 11), went on the air on January 12, 1959. When KOED began operations, OETA became the second operational educational television state network in the United States (after Alabama Educational Television, now Alabama Public Television). On December 1, 1977, KOET (channel 3) in Eufaula joined the state network as a satellite of KOED-TV, in order to serve areas of east-central Oklahoma (in some areas of that portion of the state, the northern fringes of KOET's over-the-air signal coverage overlap with that of KOED, and in other areas on the western fringe of its coverage area with KETA's signal). Finally, on August 6, 1978, KWET (channel 12) in Cheyenne signed on to serve west-central and southwestern Oklahoma, and a small portion of the eastern Texas Panhandle.

OETA's full-power stations cover roughly 80% of Oklahoma's geographic population. The only parts of the state that are not served by a full-power OETA member station are the panhandle, and the northwestern, south-central and southeastern parts of the state – low-power translators that relay the individual feeds of each of the four full-power member stations service these areas of Oklahoma instead. In 2003, the four OETA member stations began operating digital signals; in 2005, OETA began broadcasting select PBS programs in high definition. In 2006, the organization launched a full-time digital channel, OETA OKLA, devoted to local and regional programs, along with select PBS content. In December 2008, OETA began producing most of its locally produced productions in high definition.

As part of the digital television transition, on February 17, 2009 (the original date for all U.S. full-power television stations to switch to digital-only broadcasts), KETA and KOED shut down their analog signals. This was followed six weeks later on March 31, 2009, by the discontinuance of KWET and KOET's analog signals. All the low-power translator stations then switched to digital-only broadcast on June 12, 2009 (the rescheduled date for the switch to digital broadcasts on full-power stations). In March 2011, OETA moved its Tulsa operations into a new facility on the campus of Oklahoma State University–Tulsa.