Thomas De Gendt (born 6 November 1986) is a Belgian former road racing cyclist, who competed as a professional from 2009 to 2024.

Having competed for Topsport Vlaanderen–Mercator, Vacansoleil–DCM, Omega Pharma–Quick-Step and Lotto–Dstny during his career, De Gendt has taken seventeen professional victories including five Grand Tour stage victories – with at least one at each of the three Grand Tours – and five stage wins at the Volta a Catalunya between 2013 and 2021. The winner of the mountains classification at the 2018 Vuelta a España, De Gendt has also finished on the podium at the 2012 Giro d'Italia, where he was third overall.