Brian Michael Downey (born 27 January 1951) is an Irish drummer. He was a founding member of the rock band Thin Lizzy and the only other constant in the band aside from leader Phil Lynott until their break-up in 1983. Downey also co-wrote several Thin Lizzy songs. Allmusic critic Eduardo Rivadavia has argued that Downey is "certainly one of the most underrated [rock drummers] of his generation".