RTS 1 (French: RTS Un) is a Swiss public television channel owned by RTS Radio Télévision Suisse, the public broadcaster for the Romand people.

The channel first aired programmes in colour in 1968.

RTS took part in the creation of TV5 in 1984, and provides programmes for the international channel.

RTS Un is available in Aosta Valley, Italy, due to Italian self-government laws, and until the cessation of all digital terrestrial signals in Switzerland in 2019 could also be received in the border areas via spillover.

This Swiss television-related article is a stub.