Anton Cajetan Adlgasser (sometimes Anton Cajetan Adelgasser; 1 October 1729 – 23 December 1777) was a German organist and composer at Salzburg Cathedral and at court, and composed a good deal of liturgical music (including eight masses and two requiems) as well as oratorios and orchestral and keyboard works. He died at Salzburg in 1777 of a stroke suffered while playing the organ.