Fenwick signed for Queens Park Rangers in December 1980 for £110,000 and went on to make 256 appearances scoring 33 goals. Whilst at Queens Park Rangers, Fenwick made his debut for the full England side, in May 1984 as a substitute for Alvin Martin, at Wrexham. He also became the first full back to score a goal from open play in an FA Cup Final when he equalized against Tottenham Hotspur in the 1982 final.