Grand Tours Iljo Keisse (born 21 December 1982) is a Belgian former racing cyclist, who competed as a professional from 2005 to 2022.

After his victory in the 2008 Six Days of Ghent, both his A and B samples tested positive for cathine and a diuretic which has been used to mask the presence of doping agents.

[7] On 7 July 2010, the Court of Arbitration for Sport upheld an appeal by the World Anti-Doping Agency and reinstated Keisse's ban.

[8] In November, the CAS' decision was overturned by the Belgian Court of Appeals, allowing Keisse to ride the 2010 Six Days of Ghent.

[12] Another win came in 2015, at the Ronde van Zeeland Seaports; he won this race from a group of three Etixx–Quick-Step riders who had escaped earlier.