Frederik Van Lierde (born 25 May 1979) is a Belgian professional triathlete and 2013 Ironman triathlon world champion.

Van Lierde has been coached for two years by two-time Ironman champion and former world record holder Luc Van Lierde, to whom he is not related.

On 13 October 2013, Van Lierde won the same championship, becoming only the second Belgian to win the Ironman, after Luc Van Lierde.

He finished the race with a 51:02 swim, a 4:25:37 bike and a 2:51:18 marathon to capture the win in total of 8:12:29.

In March 2017, Van Lierde was attacked and robbed while training in Port Elizabeth, South Africa.