The lords of Gruuthuse (Heren van Gruuthuse, also Gruythuyse; also "lords of Bruges", Heren van Brugge) were one of the noble families of Bruges in the medieval period. It was one of several families bearing the title of "lords of Bruges" (Heren van Brugge) Their heraldic motto was Plus est en vous – Meer is in u ("there is more in you").
The family emerges in the 13th century, and its male line is extinct in 1572. Its most notable member was Lodewijk van Gruuthuse (1422 – 1492). They held several titles like Lord of Gruuthuse, Prince of Steenhuijs and Earl of Winchester.