Gustav Julius Mortensen is a 23-year-old professional football player from DEN. He currently plays for Standard Liege, wearing the number 3 shirt. He plays primarily as a Defender. He stands at 175cm tall and weighs 68kg. His preferred foot is Left. His current market value is estimated at 3M €.

His most recent move was a Free from Lyngby to Standard Liege on 2026-01-14. The reported fee was 1M €.

Throughout the Belgian Pro League 2025-2026, Gustav Julius Mortensen featured in 7 matches, averaging 1.3 tackles, 0.3 interceptions, and 2.7 clearances per game, while blocking 0.1 shots per game.