Gaspar de Witte was a Flemish painter who is known for his landscapes and gallery paintings.

Gaspar de Witte was born in Antwerp as the son of Peter de Witte II en Barbara Remeeus. He was member of a prominent painting family. His father and his brothers Peter de Witte III and Jan Baptist de Witte were all painters. Gaspar was also the godchild of Gerard Seghers, an eminent history painter of Antwerp. Gaspar de Witte trained with his father, who was specialized in landscapes, church interiors and religious paintings.

Gaspar de Witte travelled to Rome in 1646 and joined the Bentvueghels, an association of mainly Dutch and Flemish artists working in Rome. It was the custom in the Bentvueghels to initiate new members and give them a nickname (the so-called bentname). Gaspar de Witte was given the nickname Grondel ("Gudgeon"). The reason why he was named after this species of fish is not known. Around 1648 he is reported to have spent time in France.

When he returned to Antwerp he became "winemaster" (used to denote the son of a master) in the Antwerp Guild of Saint Luke in 1650. Gaspar de Witte also operated a small trading business in painting necessities. His engraved portrait by the engraver Richard Collin after a painting by Anton Goubau was published in Cornelis de Bie's 17th century book on Flemish painters called Het Gulden Cabinet.

He was the teacher of Cornelis Huysmans and possible also of Adriaen Verdoel.