Tsonga's father, handball player Didier Tsonga, is from Congo-Brazzaville, and his mother Évelyne is French. Jo's father moved to France during the 1970s to fulfill his own dreams of becoming a handball great, where he eventually met Évelyne and they married. Tsonga is nicknamed Ali, because of his facial resemblance to the boxer.[3]
Jo-Wilfried Tsonga has a younger brother (Enzo) who, much like Jo, has been inspired to play sports and is part of the French basketball program (junior). He also has an elder sister (Sasha) who is less involved with sporting ventures. His footballing cousin is Maël Lépicier who plays for Congo.[4] Tsonga and Gaël Monfils developed a good friendship from a young age, when they enjoyed mimicking all the tennis greats of the past.
As a junior, Tsonga reached a ranking of No. 2 in the world and won the US Open title. He reached four other semifinals of junior Grand Slam events. Marcos Baghdatis was a rival of Tsonga on the junior tour.