Born in Carlisle, Beattie joined Ipswich Town in July 1971, making his senior debut in August 1972. At Ipswich, Beattie was the 1973–74 PFA Young Player of the Year (the very first winner of the award), and he also won the FA Cup in 1978 and the UEFA Cup in 1981. He received his 1981 UEFA Cup winners medal in 2008, following a petition organised by Rob Finch, the ghostwriter of Beattie's autobiography, after he had missed the final due to injury
He retired due to injury in December 1981,but later returned to play for Colchester United, Middlesbrough, Harwich & Parkeston, Sandvikens IF, Kongsberg IF, Nybergsund IL-Trysil and Clacton Town.
He also earned nine caps for the England national team between 1975 and 1977. He was once described by Bobby Robson as the best England player he had ever seen