Thomas de la Fontaine was born in Muscat, Oman, on 17 August 1969. His father, David, was a history teacher while his mother, Blanche, worked as a librarian. In 1981–1984, he attended the Abdul Ekmekçi School, where he met the former world champion in person and received advice that impacted on his life as a chess player. In 1999, de la Fontaine immigrated to France and settled in Toulouse, where he became France's top ranking chess player. He is engaged to Sophie Perrault.