Yousuf Othman Qader (Arabic: يوسف عثمان قادر; born April 5, 1985) is a Qatari marathon runner. Qader represented Qatar at the 2008 Summer Olympics in Beijing, where he competed for the men's marathon, along with his compatriot Mubarak Shami. He finished the race in sixty-fourth place by fourteen seconds behind Guatemala's Alfredo Arévalo, with a time of 2:28:40. Qader also achieved his personal best time of 2:13:18 at the 2007 Hamburg Marathon.