was a Scottish football player and manager. He achieved numerous distinctions and high rankings as a prolific goal-scoring forward with six senior clubs; St Mirren, Dundee, Sunderland, Arsenal, Manchester City and Clapton Orient. He bookended his senior career playing at then non-league Queen of the South and Yeovil and Petters United. Halliday's three goals in the FA Cup proper for Yeovil give him a career total of 368 senior goals. From being player-manager at Yeovil, he went on to win trophies managing Aberdeen and Leicester City.

He is the most recent of only two players to be outright top scorer in both Scottish and English football's top divisions with 38 Dundee goals in 1923–24 and 43 Sunderland goals in 1928–29. He is the quickest player in history to 100 goals in English football's top division, taking 101 games when at Sunderland. He is the only player to score 30 or more goals in four consecutive seasons in English football's top division (achieved again when at Sunderland). He scored at least 35 league goals in each of those four seasons. He is Sunderland's most prolific goals-per-game striker with 165 goals from 175 games. His 211 goals in English football's top division with Sunderland, Arsenal and Manchester City ranks him the 20th highest scorer at that level. Of the 27 players to have scored 200 or more goals in English football's top division, only Dixie Dean scored at a more prolific rate at that level.

Managing Aberdeen, he won the 1946–47 Scottish Cup and the 1954–55 Scottish Football League. He managed Leicester City to promotion to the top division in England from winning the 1956–57 Football League Second Division.