Walter De Donder was born on July 12, 1961, in Hekelgem, Belgium. Before his career in entertainment, he worked as a baker's apprentice and for the Belgian National Railway Company. His performance background includes acting with an amateur theater group and operating his own puppet theater called Bibberlip.

De Donder is best known for his long-running roles in live-action Belgian children's television, particularly as the mayor, Meneer de Burgemeester, on the series Samson en Gert, a role he began playing in 1990. Starting in 1997, he also began playing the titular gnome in the series Kabouter Plop.

Within the context of anime voice acting, De Donder is recognized for his role as Vector the Crocodile in the Japanese anime series Sonic X, which was produced for the Flemish market in 2004 and 2005. This role stands as his primary credit in the anime genre. He has no other documented major voice roles in anime, and information on recurring collaborations or notable achievements specifically within the field of anime voice acting is unavailable.