Cardiff Amateur Athletic Club (Cardiff AAC) (Welsh: Clwb Athletau Amatur Caerdydd), is an athletics club in Cardiff, Wales. The club competes at the Cardiff International Sports Stadium and comprises five sections, each specialising in a separate sport: track and field, road running, cross country, mountain running, and road walking. Cardiff AAC athletes have won a total of 122 medals at major international championships—Olympic and Paralympic Games, World and European Championships, Commonwealth Games and the World University Games.

Formed in 1882 as Roath (Cardiff) Harriers, the club began as a cross country club, the first athletics only club in Wales. Roath Harriers runners became individual and team champions of the first South Wales Cross Country Championships, held on 7 March 1894.

Roath Harriers shared Maindy Stadium with Birchgrove Harriers from its opening in 1951 and the two clubs amalgamated to form Cardiff Amateur Athletic Club in 1968.

Lynn Davies, who was a member of Roath Harriers, was the club's first Olympian at the 1964 Olympic Games in Tokyo. Competing in the men's long jump event he won the first ever long jump gold medal for Great Britain.

Cardiff were British Athletics League champions in 1972, 1973, and 1974.