Sebastiano Bombelli (1635 – 7 May 1719) was an Italian painter, mainly active in Venice, during the Baroque period.
Bombelli was born in Udine, where he was apprenticed to his father, Valentino Bombelli, and his godfather, Girolamo Lugaro. He is claimed by some to have studied with Guercino. He is best known for his full-length portraits of the Venetian nobility, dressed in their official regalia. A style of depiction which would be also used in the next century by Alessandro Longhi. He was a mentor to the painter Fra' Galgario (Giuseppe Vittore Ghislandi).
Bombelli visited most of the courts of Germany, where he painted portraits with success. The Belvedere at Vienna possesses a portrait of Francesco de' Medici by him.