Alexander Begg Allan (born 29 October 1947) is a Scottish former professional footballer. During his career, he made over 50 appearances in the Football League. After attracting attention as an amateur player, he signed for Cardiff City in 1967 and made his professional debut soon after. However, a broken ankle and strong competition for places limited him to nine league appearances over three seasons. During his time with Cardiff, he became the first player to score a headed hat-trick in a European competition during a match against Mjøndalen IF in 1969.