The daily Irish-language programme schedule is its core service: seven hours of programming in Irish supported by a wide range of material in other languages, mostly English and French.

[8] Format In 1969, Lelia Doolan, Jack Dowling and Bob Quinn published Sit down and Be Counted, a book describing their campaign for a separate Irish-language television service.

In 1987 they set up the pirate television station Teilifís na Gaeltachta, after years of delays, including the sudden death of their technician who was to build the transmitter.

In 1989, Ciarán Ó Feinneadha, one of the members of Coiste ar son Teilifís Gaeltachta, moved to Dublin and set up a similar organisation in the capital called Feachtas Náisiúnta Teilifíse (FTN).

[9] In the early 1990s, Irish language programmes amounted to only 5% of total programming broadcast by RTÉ, and was reduced significantly during the summer months.

The outgoing coalition parties of Fianna Fáil and the Progressive Democrats called for the establishment of an Irish language television station in their 1989 manifestos.

In fewer than six months from the launch of Teilifís na Gaeilge, almost 65% of Ireland's television sets were able to receive the channel and the nightly audience had risen to 250,000 viewers.

Initial criticisms of the planned station came from journalist Kevin Myers who derided TnaG as a white elephant, calling it 'Teilifís De Lorean', in a reference to the ill-fated DeLorean Motor Company.

The Act also changed the English-language title of the Chief Executive of TG4 to "Director General" in line with that of the head of RTÉ, and in the Irish language from "Ceannasaí" to "Ardstiúrthóir".

[22] The Irish language enthusiast Seán Tadhg Ó Gairbhí wrote Súil eile (published by Cois Life in 2017).

The main aim of its new schedules was to provide "national resonance"[clarification needed Please explain this term] and to compete with BBC Two and Channel 4 for Irish audiences.

[31] On Saint Patrick's Day 2009, live coverage of the All-Ireland Finals in the AIB Club Championships on TG4 achieved very high audience ratings for the channel.

[33] Some of the most popular programmes included: Glór Tíre (country and western reality competition) – 90–110,000; Rásaí na Gaillimhe (political comedy drama); Ros na Rún (soap opera), GAA Beo (GAA sport) – 50–100,000; Fíorscéal, Cogar (documentary); Seacht (university drama); Nuacht TG4 (news); 7 Lá (weekly review); Paisean Faisean (dating programme), Feirm Factor (reality television); and An Jig Gig.

Cúla4 na n-Óg began airing from 07:00 for pre-school children with programmes such as Tar ag Spraoi Sesame, Dora the Explorer and Wow!

In 2006 a strand called Ponc began airing with teen programming such as Pimp My Ride, MTV Cribs, 8 Simple Rules, America's Next Top Model, What I Like About You and South Park.

Other series aired on the channel include Army Wives, Cold Case, Gossip Girl, One Tree Hill, The Starter Wife, True Blood, Two and a Half Men, Vampire Diaries, Without a Trace, Carnivàle, Curb Your Enthusiasm, Eve, Everwood, Invasion, Lipstick Jungle, The O.C., and Survivor.

With the launch of Sky Atlantic in 2011, they now hold first rights to European (Ireland, UK, Germany, Austria, Italy and Switzerland) broadcasts of HBO shows.

[42] TG4 broadcast the first live League of Ireland Women's Premier Division game from Tolka Park on 2 October 2021 with hosts Shelbourne beating DLR Waves 1:0.

On 24 September 2007, TG4 began broadcasting South Park in Irish, on Síle, with the more adult content removed but also made available on Saturday nights.

Repeats of Irish traditional music programmes from RTÉ feature in the schedules such as The Pure Drop and Come West Along the Road.

The judging panel consisted of Maura Derrane (former Ireland AM presenter), Alan Dukes (former Minister for Agriculture) and Seán O Lionaird (dairy farmer from Cork).

In 2007 TG4 won major critical acclaim for their political satirical comedy The Running Mate and for the programme Seacht which follows the lives of seven college students in Belfast.

Set during the week of the Galway Races, it is a drama-comedy starring Don Wycherley, Ruth Bradley, Olga Wherly, Hughie McGarvey and Owen Roe.

The comedy initially centred around the office of the acting-chairman of ACT (An Chomhairle Teanga/The Language Commissioner) played by Risteárd Cooper as he fought to save the organisations from An Bord Snip Nua.

It also actively commissions documentaries such as the acclaimed and popular Amú series of travel programmes which launched the career of Hector Ó hEochagáin, one of a number of TG4 presenters who have gone on to success at other channels.

TG4 only re-dub cartoons while live action series remain in English, such as the Australian drama H2O: Just Add Water and the American sitcom Lizzie McGuire.

In the early years of TnaG the channel broadcast many European programmes with Irish dubbing however this policy has since stopped in favour of US programming in English.

The opening sequence featured a number of Irish scenes from across the Island of Ireland, including Belfast and Dublin, and finished with a lighthouse, the light of which beamed the logo onto the screen.

[71] In February 2021, TG4 launched a set of six new idents with a strong focus on Irish folklore with CGI and 4D elements to the designs, these were produced between TG4 and Red Bee Creative.

In March 2005, TG4 began broadcasting from the Divis transmitter near Belfast, as a result of agreement between the Department of Foreign Affairs and the Northern Ireland Office.