The Diocese of Krk (Croatian: Krčka biskupija; Latin: Dioecesis Veglensis) is a Latin Church ecclesiastical territory or diocese of the Catholic Church active on the Croatian islands of Krk, Rab, Cres and Lošinj, as well as a few smaller ones and also a mission serving the Croatian people of New York: Blessed Ivan Merz in Astoria NY under the Brooklyn Diocese.

[1][2] Under Bishop Antun Mahnić (1896–1920), the Altslawi academy was established in 1902, and existed until 1927.

The diocese's patron is Saint Quirinus of Sescia (locally called Sveti Kvirin).

Bartholomaus Bozarich was present at the assembly of bishops in 1849 and his successor was a member of the First Vatican Council.

The Diocese of Ossero (Lusin, Absor, Auxerensis), with its see at Osor, was older; Pope John VIII wrote to its bishop in 870.