Guy VII de Mauvoisin, Baron of Rosny

Guy VII de Mauvoisin (born c. 1307, died after 1360) was baron of Rosny-sur-Seine and the eldest son of Guy VI de Mauvoisin and Laure de Ponthieu. Around 1328 he married Roberte de Beaumetz, châtelaine of Bapaume, whose Artois lordships passed to their daughters.

The marriage produced three daughters, Laure, Béatrix and Marguerite, but no son. After Guy's death his brother Amaury sold Rosny to his daughter Béatrix in 1365.