David James Mattacks is an English rock and folk drummer, best known for his work with British folk rock band Fairport Convention.

Fairport Convention are an English folk rock band, formed in 1967 by guitarists Richard Thompson and Simon Nicol, bassist Ashley Hutchings and drummer Shaun Frater. They started out influenced by American folk rock, with a set list dominated by Bob Dylan and Joni Mitchell songs and a sound that earned them the nickname "the British Jefferson Airplane". Vocalists Judy Dyble and Iain Matthews joined them before the recording of their self-titled debut in 1968; afterwards, Dyble was replaced by Sandy Denny, with Matthews later leaving during the recording of their third album.