TLC is an American premium multinational cable and satellite television network owned by the Networks division of Warner Bros. Discovery. First established in 1980 as The Learning Channel, it initially focused on educational and instructional programming. By the late 1990s, after an acquisition by Discovery, Inc. earlier in the decade, the network began to pivot towards reality television programming—predominantly focusing on programming involving lifestyles and personal stories—to the point that the previous name with "The Learning Channel" spelled out was phased out in favor of its initialism.

As of November 2023^[update], with its programming primarily dedicated to the nine-series 90 Day Fiancé universe, comprising 31% of the shows carried by the channel, TLC is available to approximately 71,000,000 pay television households in the United States—down from its 2011 peak of 100,000,000 households.

TLC's history traces to the 1972 formation of the Appalachian Educational Satellite Project (AESP), a distance education project formed by the Appalachian Regional Commission (ARC), in participation with the Education Satellite Communication Demonstration (ESCD), a partnership with the Department of Health, Education, and Welfare and NASA intended to transmit instructional, career and health programming via satellite to provide televised educational material to public schools and universities in the Appalachian region. ARC submitted a proposal to participate in the ESCD and use the ATS-6 communications satellite (launched into orbit in 1974) to disseminate "career education" programming to teachers at no cost; the consortium set up 15 earth station receiver sites across eight states in conjunction with local education service agencies.

The ATS-6 temporarily ceased service to the Appalachian region after being re-orbited to India in September 1975; by the time the satellite reoriented to the United States the following year, the number of earth receivers used to transmit AESP content increased to 45 sites in Pennsylvania, Kentucky, Maryland, Virginia, West Virginia, Tennessee, Alabama, Georgia, North Carolina and South Carolina (some of which also acted as relays to local television stations in the region). All programming offered through the project was accepted for academic credit at 12 universities in the region. In October 1978, NASA disclosed the ATS-6 would suspend transmissions for 12 months due to transmission problems with the satellite. As a result, ARC decided to purchase transponder time on the commercial Satcom I communications satellite, in order to continue its distance education offerings.

The non-profit Appalachian Community Service Network (ACSN) was incorporated in April 1980, maintaining a board of directors appointed by the Appalachian Regional Commission. The ACSN television service launched in October 1980 as ACSN – The Learning Channel; unlike the closed-circuit AESP, the network distributed its programming available directly to cable systems for home viewing. Its programming also expanded to include "informational" content. (NASA immediately launched NASA TV as the ACSN's internal replacement.) By 1982, ACSN claimed that it "achieved the fastest rate of growth of all basic cable programming services", with availability on around 70 cable affiliates reaching 1.5 million subscribers; by this point, 70 universities granted academic credit for telecourses carried on the network. On January 1, 1984, the network shortened its name to The Learning Channel.

The channel mostly featured documentary content pertaining to nature, science, history, current events, medicine, technology, cooking, home improvement, and other information-based topics. A notable example of such programming was Sew, What's New?, a fashion design show presented by George W. Trippon. These were more focused, more technical, and of a more academic nature than the content that was being broadcast at the time on its eventual rival, The Discovery Channel, which launched in 1985. TLC was geared toward an inquisitive and narrow audience during this time, and had modest ratings. An exception to this viewership commonality was Captain's Log (produced and hosted by Mark Graves, also known as Captain Mark Gray), a weekly primetime boating safety series that aired from 1987 to 1990; the program often achieved between a 4.5 to 6 rating share and was the highest compensated series in the history of TLC with over 30 times the compensation of any other series on the network.^{[citation needed]}

In 1986, Infotech, Inc.—then-owner of the Financial News Network (FNN)—acquired a 51% interest in The Learning Channel for $3 million; the American Community Service Network retained a 31.5% share of the network, with the remaining 17.5% owned by network management.

On February 15, 1991, The Discovery Channel, Inc.—owners of the namesake cable channel—announced it had reached an agreement to acquire The Learning Channel from ACSN and Infotech (the latter of which was in the process of a bankruptcy-led asset liquidation to repay creditors, subsequently resulting in the sale of the Financial News Network to a joint venture of NBC and Cablevision that integrated the network with rival financial news channel CNBC) for $12.75 million (equivalent to $29.43 million today). Under Discovery, The Learning Channel continued to focus primarily on instructional and educational programming for much of the 1990s; however, in what preceded its later expansion of such content, it also began to include shows less focused on education and geared more toward attracting popular consumption and mass marketing. In 1992, the network's name was shortened to "TLC", although the full name remained in use on alternating basis.