Dionys van Nijmegen, was an 18th-century painter from the Northern Netherlands.

He was born in Rotterdam as the son of Elias van Nijmegen. He was a pupil of his father and Jacob de Wit and became a member of the Rotterdam Guild of St. Luke in 1743. He is known for portraits, wall and ceiling decorations. He was the father and teacher of Gerard van Nijmegen [nl].

He died in Rotterdam.