The 1929–30 season was the 29th season of competitive football played by Cardiff City F.C. and the team's first year in the Second Division of the Football League since being relegated from the First Division the previous year. They finished in eighth position overall and the season saw several first team players sold to raise funds to cover a drop in attendance figures following relegation. The season also held the first South Wales derby in the Football League between Cardiff and Swansea Town.