Karel Slabbaert was a Dutch painter and draftsman. The artist worked in Middelburg between 1634 and 1654. His work includes portraits, genre scenes and still lifes. He was a Dutch Golden Age painter who died young.
Slabbaert was born in Zierikzee. His earliest dated work is recorded as 1641 and he became engaged to Cornelia Bouwers of Rotterdam on 8 April 1645. His works show familiarity with Rembrandt's studio and he was in Amsterdam in 1645 while being a member of the painter's guild in Middelburg the same year. He became dean of the Middelburg guild in 1653, but he died there the next year.