Triple J (stylised in all lowercase) is a government-funded, national Australian radio station founded in 1975 as a division of the Australian Broadcasting Corporation (ABC). It aims to appeal to young listeners of alternative music, and plays more Australian content than commercial networks.

The station was set up under the Gough Whitlam government, wanting to extend the appeal of the ABC to young Australians. Initially broadcasting as 2JJ or Double Jay from 19 January 1975, it stood apart from commercial stations with its lack of private advertising and its fringe music programming. Following a transition to FM in 1981, the station rebranded as 2JJJ or Triple J as it expanded regionally throughout the 1990s. Two spin-off digital stations were launched in the early 2010s– Triple J Unearthed, which plays only local, unsigned musicians; and Double J, which aims to appeal to more contemporary audiences. Triple J used to dominate national ratings in the 18–24 year old demographic, but its audience has declined since 2015 with the rise of streaming media.

Triple J continues to have a significant impact on the Australian music landscape, supporting major music festivals and domestic tours, and organising its own events like One Night Stand. Every year, it broadcasts the Hottest 100, a public poll of the years' most popular music, and runs the J Awards, a music awards series. Triple J annually champions Ausmusic Month and founded the nationwide Ausmusic T-Shirt Day initiative in 2013. Unearthed, the network's online music discovery platform, provides pathways for independent artists to be broadcast on the network. However, Triple J has been criticised for promoting a homogenous national music scene.