Jan van Os (23 February 1744 – 7 February 1808) was a Dutch painter and a member of the renowned Van Os family of artists.

He was taught by Aert Schouman in The Hague, where he would spend the rest of his life.

In 1775, he married Susanna de La Croix, an able pastellist and the daughter of the deaf-mute portraitist Pieter Frederik de la Croix.

His floral still lifes were painted in the style of Jan van Huysum, with the flowers usually presented on a marble ledge against a green background.

Jan van Os was the teacher of his children as well as Petronella van Woensel, a friend of his daughter Maria.