Cornelis Wilhelmus Pieter "Cor" Vriend (born 8 November 1949) is a former long-distance runner from the Netherlands, who mainly competed in the marathon. He participated in two consecutive Summer Olympics for his native country; in 1980 (Moscow, 41st place) and 1984 (Los Angeles, 39th place). During the early 1980s he was overshadowed by his fellow countryman Gerard Nijboer. His personal best at the marathon was 2:11:41, set at the 1984 Maassluis Marathon, finishing first in the race.