Sebastiano Bombelli (baptized October 15, 1635 in Udine; May 7, 1719 in Venice) was an Italian portrait painter of the Baroque in Venice.
Bombelli studied with his father Valentino Bombelli and his godfather, the Mannerist painter Girolamo Lugaro in Udine. Perhaps he also studied with Guercino. From the early 1660s he was in Venice. There he mainly studied the works of Paolo Veronese. He is known for his portraits of Venetian noblemen in official state robes. According to Sandrart (1683), he was initially known for historical paintings in the style of Veronese (which, however, are not yet known). He also visited Germany and Austria, where a portrait of Francesco de Medici hangs in the Belvedere in Vienna. Among his students in Venice is Fra Galgario.