Baldwin IV (1108 - November 8 1171) was count of Hainaut from 1120 to his death. Baldwin married Alice of Namur, heiress of Namur, and had the following issue:

• Yolande (1131-1202), married Hugh Iv, Count of St Pol
• Baldwin (1134-1147)
• Agnes (1142-1168)
• Geoffrey, Count of Ostervant (1147-1163)
• Lauretta (1150-1181), married Bouchard IV, Count of Montmorency
• Baldwin V, also count of Flanders by his marriage to Margaret I of Flanders

See also: Counts of Hainaut family tree