Piet van Katwijk was a Dutch road cyclist who was active during the 1970s. Early in his career Van Katwijk competed in the road race at the 1972 München Olympics where he finished 11th in a group of 25 riders who were just over 30 seconds behind the race winner. Arguably his biggest win came just a year later with victory at the multi-stage Milk Race in England. During the decade he also had some notable victories at home with multiple stages of the Olympia’s Tour and a win at the 1974 edition of the Acht van Chaam one-day race. Van Katwijk was consistent at the Spring classics in Belgium and France, finishing third on two occasions at Gent–Wevelgem (1977, 1980), along with fifth at Paris–Roubaix in 1977 and fifth at the Tour of Flanders in 1979. His younger brother Fons rode in the 100 kilometres team time trial at the 1976 Montréal Olympics.