Full name is Thiemo Carsten Jannick de Bakker. His mother Carlieke, introduced her son to tennis when she would bring him to local club and he taught himself how to play. At age six he started practising with coaches from Dutch Tennis Federation.
Earned his first swimming diploma at age three and started playing at a soccer club at age four. Ruud Thijssen, father of Nicole Thijssen (played for junior Fed Cup team) was coach at his club and recognized his talent. He let Thiemo join practice even though he was still very young.
Has one older (Yori) and one younger brother (Kayo).
Finished as No. 1 junior in world in 2006, capping his career with title at Wimbledon juniors (d. Gawron). Also won four other junior titles, in Costa Rica, Australia, Italy and Great Britain. Advanced to SF at Roland Garros (l. to Bester).
Considers clay his best surface and forehand as best shot. Has a 4-5 career record in Davis Cup play (4-4 in singles) in four ties. Coached part-time by Rohan Goetzke, the technical director of the Dutch Tennis Federation, and mentored by Richard Krajicek.