Omar Colley was born on October 24, 1992 in Lamine, Gambia. He started his career playing for Wallidan FC, before moving to Real de Banjul. There, at the age of 20, he made a significant contribution to winning the championship in 2012.

His journey in Europe began in 2013 with the Finnish club KuPS. He stayed in Finland for two years, played in 74 matches, scored seven goals and provided one assist. The next stop of his career was Djurgårdens of Sweden, where he made 50 appearances and scored five goals.

In 2016, Colley became a resident of Belgium on behalf of Genk. His performances established him as one of the team’s top defenders, making 95 appearances and scoring five goals.

In the summer of 2018, Colley took the next big step in his career by moving to Sampdoria. The Italians spent around 9,000,000 euros to acquire him. The Gambian centre-back played for five seasons in Serie A, making 136 appearances, scoring three goals and contributing one assist.

Then in January 2023, he moved to Besiktas, where he made 46 appearances and scored eight goals. With Besiktas he won the Turkish Cup and the Turkish Super Cup.

At international level, Colley is a mainstay for the Gambia national team, with whom he has made 51 appearances, captaining his country as well.