Johan Slager (Amsterdam, 8 June 1946 – 22 January 2025 ) was a Dutch guitarist. He co-founded Kayak in 1972, together with Ton Scherpenzeel, Pim Koopman, and Max Werner. Before that he played with Scherpenzeel and Koopman in High Tide Formation from 1970 to 1972. Slager played on nine Kayak albums, until the group stopped in 1982. In the late 1990s he participated in a few reunion concerts, but he was not part of the band when Kayak reformed in 1999.