Thomas Petrus A. Koenis (born 11 December 1989) is a Dutch retired basketball player. Standing at 2.10 m (6 ft 11 in), he played at the center position. He started his career with the Den Helder Seals in 2007, before signing with West-Brabant Giants in 2009. After two seasons for the Giants, Koenis signed with Donar. In 2015, he signed with ZZ Leiden where he stayed for two seasons before returning to Donar. Koenis played 15 season of professional basketball, with nine of them being with Donar. After his career, Koenis' number 14 was retired by the club to honour him.