Hood signed for Celtic in March 1969 for a £40,000 transfer fee, and quickly established himself in a talented group managed by Jock Stein including the Europe-conquering Lisbon Lions and the emerging highly rated youth players such as Kenny Dalglish dubbed the Quality Street Gang. After playing a part in the team's run to the 1970 European Cup Final, he was not selected for the match in Milan as Celtic lost to Feyenoord. He scored the winning goal against Rangers in the 1971 Scottish Cup Final replay as Celtic won 2–1, and also scored the first goal in the 1974 Scottish Cup Final, a 3–0 victory over Dundee United.