Julien Ariel De Sart (born 23 December 1994) is a Belgian professional footballer who plays as a defensive midfielder for Qatari club Al-Rayyan.
He began his career in the youth academy of Standard Liège. De Sart went on to sign his first professional contract with the club's senior team in 2013, making his debut in that same year. In 2016, he signed for Middlesbrough, who would go on to achieve promotion to the Premier League that same season. He rarely played at the club, and went on loan to Derby County for more first-team experience. Following his parent club's relegation, he was sent on loan to Zulte Waregem.
De Sart represented his national country at under-16, under-17, under-18, under-19 and under-21 level.
