Julien Ariel De Sart (born 23 December 1994) is a Belgian professional footballer who plays as a defensive midfielder for Qatari club Al-Rayyan. On 22 August 2013, he made his debut in the UEFA Europa League against Belarusian FC Minsk in a 0-2 away win. He played the full game. He's a youth exponent from the club. He is the son of Jean-François De Sart who has been a board member of Standard Liège, and the elder brother of Alexis De Sart who previously played for Standard Liège. He made his league debut at 25 August 2013 against R.A.E.C. Mons in a 0-2 away win, coming off the bench in the first half for an injured Yoni Buyens. After 83 minutes he was sent off with a second yellow card. At 24 November 2013, he scored the only goal against R.A.E.C. Mons.
On 1 February 2016, it was confirmed that De Sart had joined English club Middlesbrough of the Championship side on a three-and-a-half year contract for an undisclosed fee.
