Derek Austin Cornelius (born 25 November 1997) is a Canadian professional soccer player who plays as a centre-back for Ligue 1 club Marseille and the Canada national team.

He ended that year by being invited to the CSKA Moscow Reserve Camp and by playing in the U21 Provincial and Men's Regional leagues, scoring 22 goals in 30 games.

[4] He spent two seasons with the main team,[5] but was unable to play due to FIFA rules for underaged players.

[6][7] With VfB Lübeck he won the Schleswig-Holstein Cup two consecutive seasons and made an appearance in the 2015–16 Regionalliga Nord.

[5] During the winter break of the 2016–17 season, Cornelius was signed by Serbian SuperLiga side FK Javor Ivanjica after successful trials.

[9] On 18 January 2019, Cornelius returned to his native Canada and signed with MLS side Vancouver Whitecaps FC.

[25] In March 2021 Cornelius was named to the Canadian U-23 roster for the 2020 CONCACAF Men's Olympic Qualifying Championship.

[26] He served as captain throughout the tournament, and scored a goal against Honduras in Canada's final group stage match.

[28] He would make his debut for Canada on 9 September 2018, starting and playing the entire match in an 8–0 victory over the U.S. Virgin Islands.