"[1] While Jefferson County, home to Louisville, began the process to build what became WFPK-TV (now WKPC-TV) on channel 15 in 1957, and the station signed on the next year,[2][3] the impetus for what became KET came on July 22, 1959, when O. Leonard Press, the director of the radio department at the University of Kentucky (UK)—owner of educational radio station WBKY, on air since 1940—proposed a statewide educational television network that would include studios at the university, interconnection with other universities, and a transmitter system to deliver educational programs to schools.

[4] Press touted a system incorporating WFPK-TV as well as complete coverage of the Commonwealth with the capacity to "stamp out illiteracy" and ensure universal teaching of basic school subjects.

[5] He also pushed for the entire network to be built at once to ensure that rural areas, which most needed such a service, were just as well-served as Kentucky's population centers.

[6] The network took an important step forward when the Federal Communications Commission (FCC) agreed to designate 10 new UHF television channels in the state for non-commercial educational use in August 1961; the original design did not include the transmitters at Elizabethtown or Owenton (as the existing WFPK-TV was included), though it did provide for programs to originate from Lexington, Louisville, or Murray.

[7] The plan gained the support of governor Bert T. Combs,[8] and the 1962 Kentucky General Assembly passed a trio of bills to set up the Kentucky Authority for Educational Television, enable the State Board of Education to lease facilities, and allow the state to issue revenue bonds to finance construction.

[13] Other state needs were prioritized: in education, these included issues in Jefferson County, low teacher pay, and transportation problems.

[15] Schools, meanwhile, continued to depend on sources such as MPATI and commercial stations in bordering states, such as WSAZ-TV in Huntington, West Virginia.

However, MPATI increased its fees,[15] and WSAZ-TV dropped the mathematics program it was carrying due to scheduling difficulties, affecting 2,700 students in eastern Kentucky.

[23][24] Federal matching funds were applied for and received from the Department of Health, Education, and Welfare and the Appalachian Regional Commission,[25] while the FCC granted the 12 construction permits later in the year.

[31] By May 1968, work on the Lexington and Somerset transmitters had been completed,[32] and KET had announced its initial array of 19 in-school programs, mostly for elementary school students.

[35] However, Taylor Mill met with citizen protest despite being approved by the city council, while sites in Covington would interfere with a new instrument landing system for the Greater Cincinnati Airport.

[36][37] As a result, KET opted to return to Taylor Mill, in spite of opposition whipped up by a local housewife who fretted the facility would be a hazard to aviation and generate interference to reception of other TV stations.

[40] That first day, eight transmitters opened, at Ashland, Bowling Green, Elizabethtown, Lexington, Madisonville, Morehead, Owenton, Somerset, plus two dependent translators at Hopkinsville and Owensboro.

[52] In Paducah, unsuccessful commercial station WDXR-TV was donated to the network; it was rebuilt and returned as WKPD in 1979,[55] and a full-power Owensboro transmitter, WKOH-TV channel 31,[56] started operating on February 14, 1980.

[57] After the sign-on of WKOH, the network was broadcasting over a total of 15 transmitters throughout the state and on eight low-power translator stations, primarily in eastern Kentucky.

In 1989, country musician Waylon Jennings earned his GED by watching tapes of the KET programs on his tour bus.

The network was in part insulated by a timing quirk: federal construction credits from the new facilities in Paducah and Owensboro accrued to KET in 1980 and 1981 and offset most of the state's budget cuts.

Schools were outfitted with satellite dishes as well as keypads designed to provide two-way communication between instructors in Lexington and students throughout the state, inspired by a football play predictor game at a Lexington sports bar;[78] KET reached an agreement with the maker, NTN Communications, to use its technology.

[81][82] The program was then rolled out statewide in the wake of the Kentucky Supreme Court finding the state's education system unconstitutional.

[88] That October, KET opened a 67,000-square-foot (6,200 m2) expansion of its Lexington facility, which was dedicated as the O. Leonard Press Telecommunications Center in this honor.

[91] An agreement was reached between WKPC-TV and the Kentucky Authority for Educational Television in December 1996,[92] by which KET acquired certain technical assets, including the land on which their shared transmission tower in New Albany, Indiana, sat, and the license.

[99] Gaines Fox retired at the end of 2002, having led KET through its digital television deployment and increased private support for the broadcaster.

[104] However, KET was one of the harder-hit PBS members by the Great Recession; in 2008, it lost $1.8 million in funding from the state of Kentucky and cut its staff by 18 percent.

[109] KET's distance learning offerings transitioned to online-only delivery before being discontinued in 2018 after 30 years due to state budget cuts in Kentucky.

On November 15, 1974, KET debuted Comment on Kentucky, a weekly public affairs program and political roundtable hosted by Al Smith, a newspaper publisher from Russellville.

[114] After Smith's retirement, Ferrell Wellman hosted Comment on Kentucky until 2013;[115] he was replaced, first on an interim and then on a permanent basis, by Bill Bryant, news anchor for Lexington commercial station WKYT-TV.

[124] 1995 saw the debut of Kentucky Life, a feature magazine originally hosted by Byron Crawford of The Courier-Journal and later by Dave Shuffett from 1999 to 2015.

[125] From 2015 to 2022, former baseball player Doug Flynn was host;[126] he was replaced by Chip Polston, a frequent on-air volunteer during KET's pledge drives, starting with season 28 in January 2023.

WCVN-TV in Covington began ATSC 3.0 broadcasts on June 5, 2023, as part of a partnership with Public Media Connect, the public broadcaster serving the Cincinnati area; KET provides transmission capacity in 3.0 format for WCET and WPTO (as well as datacasting capabilities for both organizations) and vice versa in 1.0 format, with fiber delivering signals between Lexington and Dayton, Ohio.

[135] The Owensboro translator was taken out of service in 1974 when its location, the Daviess County Vocational School, was demolished; no good local KET signal was available there until WKOH-TV was built in 1979.