The channel was founded in 1972 by the Department of Health, Education, and Welfare and NASA as the Appalachian Community Service Network, and was an informative and instructional network focused on providing real education through the medium of television; it was distributed at no cost by NASA satellite.
ACSN was privatized in 1980, and its name was changed to "The Learning Channel" in November of that year; the name was subsequently shortened to "TLC." (NASA immediately launched NASA TV as the ACSN's internal replacement.) The channel mostly featured documentary content pertaining to nature, science, history, current events, medicine, technology, cooking, home improvement, and other information-based topics. These are often agreed to have been more focused, more technical, and of a more academic nature than the content that was being broadcast at the time on its rival, The Discovery Channel. The channel was geared toward an inquisitive and narrow audience during this time, and had modest ratings except for the boating safety series Captain's Log with Captain Mark Gray (hosted by Mark Graves, a USMC Vietnam Vet 1967–70, Entertainer, Escape Artist, Magician, and TV Writer/Producer/Host). Captain's Log aired on TLC from 1987 to 1990. It achieved between a 4.5 to 6 share in the ratings and was the highest compensated series in the history of TLC with over 30 times the compensation of any other TLC series. Mark Graves AKA "Captain Mark Gray" was also allowed to sign yearly rather than quarterly contracts. He decided to not seek another contract renewal when Discovery acquired TLC in 1990 and moved its operations from Virginia to Denver, Colorado.
By the early 1990s, The Learning Channel was a sister channel to the Financial News Network (FNN), which owned 51 percent of the channel with Infotechnology Inc. After FNN went into bankruptcy in 1991, the Discovery Channel's owners went into discussions to purchase The Learning Channel. An agreement was made with FNN and Infotech to buy their shares for $12.75 million. The non-profit Appalachian Community Service Network owned 35 percent of the network, and was also bought out.
The Learning Channel continued to focus primarily on instructional and educational programming through much of the 1990s, but began to air shows less focused on education and themed more toward popular consumption and mass marketing; these would be later expanded.
TLC still aired educational programs such as Paleoworld (a show about prehistoric creatures), though more and more of its programming began to be devoted to niche audiences for shows regarding subjects like home improvement (HomeTime and Home Savvy were two of the first), arts and crafts, crime programs such as The New Detectives, medical programming (particularly reality-based shows following real patients through the process of operations), and other shows that appealed to daytime audiences, particularly housewives. This was to be indicative of a major change in programming content and target audience over the next few years.
Perhaps due to poor ratings from a narrow target audience, TLC began to explore new avenues starting in the late 1990s, deemphasizing educational material in favor of entertainment. "Ready Set Learn", the network's children's program block, was slowly reduced through the years as the network deliberately redirected viewers towards the full-day lineup of children's programming on Discovery Kids. The block was dropped completely in late 2008, and Cable in the Classroom programming, meant for recording by teachers, had completely disappeared by the early 2000s.
In 1998, the channel began to distance itself from its original name "The Learning Channel", and instead began to advertise itself only as "TLC". During this period, there was a huge shift in content, with most new programming being geared towards reality-drama and interior design shows. The huge success of shows like Trading Spaces, Junkyard Wars, A Wedding Story, and A Baby Story exemplified this new shift in programming towards more mass-appeal shows.
This came at a time when Discovery itself was overhauling much of its own programming, introducing shows like American Chopper (which Discovery moved to TLC for a time). Much of the old, more educationally focused programming can still be found occasionally dispersed amongst other channels owned by Discovery Communications. Most of TLC's programming today is geared towards reality-based drama or interests such as home design, emergency room or medical dramas, extreme weather, law enforcement, dating, and human interest programs.
On March 27, 2006, the network launched a new look and promotional campaign, dropping the "Life Unscripted" tag and introducing a new theme, "Live and learn", trying to turn around the network's reliance on decorating shows and reality programming. As part of the new campaign, the channel's original name, "The Learning Channel", returned to occasional usage in promotions. The new theme also played on life lessons, which featured heavily in the network's advertising and promotional clips. This campaign used humor to appeal to a target audience in their 30s.
In early March 2008, TLC launched a slightly refreshed look and promotional campaign, alongside a new slogan: "Life surprises". This new slogan came as TLC began to shift even more to personal stories, and away from the once-dominating home improvement shows. Programs focused on family life became the core of the channel. Jon & Kate Plus 8, which by 2008 was the highest-rated program on TLC, and Little People, Big World were joined by 17 Kids and Counting (which became 18 Kids and Counting and then 19 Kids and Counting as the Duggars, the family that the series centers on, expanded), and Table for 12 in 2008 and 2009 respectively. The series Toddlers & Tiaras also debuted in 2008, and proved popular enough to spawn a spin-off in 2012, Here Comes Honey Boo Boo, focusing on the family life of recurring contestant Alana "Honey Boo Boo" Thompson, which was canceled in 2014. Also premiering on TLC in 2009 was Cake Boss, which focuses on the head baker at Carlo's Bakery and his staff, who mostly consist of his family.
A high definition simulcast of TLC was launched on September 1, 2007. It is currently available on many cable and satellite systems in the United States, Mexico and Canada, including Bell TV, Cogeco, Cox, Dish Network, DirecTV, Shaw Cable, Rogers Cable, Telus, Mediacom, insight Communications, Bright House Networks, Charter Communications, Time Warner Cable, Verizon FiOS and Comcast.
OSN — the leading paid platform in the Middle East and North Africa — launched TLC HD and broadcast it with the Discovery Network, using the same form as the American TLC channel and adding new exclusive Arabic-English programs from its production as "Nidaa".
TLC's American feed is available in Canada on most cable and satellite providers, as it is authorized for carriage as a foreign cable television service by the Canadian Radio-television and Telecommunications Commission; save for a few differences it features the same programming schedule as that seen in the United States.
The Latin American TLC HD, was launched on December 1, 2009, exclusively in high-definition, in the same style as the American channel (most of TLC's programming is available in standard-definition on Discovery Home & Health). On November 1, 2011, the Latin American version of Discovery Travel & Living was relaunched as TLC: Travel & Living Channel, which now also has a dedicated feed for Brazil.
An English-speaking version of the channel was originally launched in 1994 across Europe and was subsequently renamed Discovery Home and Leisure and later Discovery Real Time as part of Discovery's slate of themed channels. TLC relaunched in the UK and the Republic of Ireland on April 30, 2013.
In early 2013 the channel launched in Romania with a record rating.
In early 2013 the channel launched in Bulgaria.
In November, 2016, TLC began to appear free, before that TLC was payment channel in Finland.
In November, 2011, TLC Portugal debuted on ZON TV distributor and satellite services.
On October 3, 2011, TLC Greece debuted on the Conn-x TV IPTV and OTE TV satellite services.
TLC Germany launched on April 10, 2014 on cable, IPTV and satellite services in both HD and SD.
A Norwegian version of the channel was launched on March 4, 2010 as TLC Norway, replacing the European version of Discovery Travel & Living in Norway.
On October 1, 2010, the Polish version of Discovery Travel & Living was relaunched as TLC Poland, replacing the European version of Discovery Travel & Living in Poland.
TLC Balkans was also launched on October 1, 2010, replacing the European version of the "Travel & Living Channel" in Slovenia, Croatia, Serbia, Macedonia and Bulgaria. TLC Balkans' playout is from Belgrade, Serbia.
On July 4, 2011, a Dutch version was launched, time sharing with Animal Planet's standard definition feed. Animal Planet remained a 24-hour service for high-definition viewers. TLC became a 24-hour channel on January 8, 2013. It is also available in HD.
On June 3, 2014, the Swiss cable provider UPC Cablecom launched TLC in Switzerland.
On November 6, 2015, TLC Turkey began broadcasting replacing CNBC-e channel.
On September 1, 2010, the Asia Pacific versions of Discovery Travel & Living were relaunched as TLC, with the acronym standing for "Travel and Living Channel".
An Indian version was launched in 2006 under the jurisdiction of Discovery Channel. It was relaunched as TLC on September 1, 2010.
A South Korean version was launched in December 4, 2013 under the Discovery Communications and CMB. The channel was replaced EXF in May 2016.
Available across sub-Saharan Africa on the DStv satellite service.
On September 1, 2011, the South African feed of TLC replaced the Discovery Travel & Living channel on TopTV. In 2013 TopTV lost the channel to DStv.