His three known legitimate children were named Magdalena, born 1632; Willem, known as the Younger, also a marine painter, born 1633; and Adriaen, a landscape painter, born 1636.
His marriage was stormy, at least in its later years. David Cordingly relates that Willem the Elder fathered two children out of wedlock in 1653, one “by his maidservant, and the other by her friend. Nine years later the Elder and his wife went through a legal separation, ‘on account of legal disputes and the most violent quarrels’. The immediate cause of the dispute was his affair with a married woman.” Michael S. Robinson noted that “on 17/27 July 1662, he and his wife agreed to part.