Jacques was born to the prominent Lalaing family in the County of Hainaut, the eldest son of Guillaume de Lalaing and Jeanne de Crequy. Jacques had three brothers: John who was provost of Saint-Lambert's Cathedral in Liege, Philippe who was a godson of Philip the Good, and Antoine who was killed by the Swiss while fighting for the Duke of Burgundy Charles the Bold. Jacques also had a half-brother named John who was the Lord of Haubourdin. Additionally, Jacques had three sisters: Yoland who married the Lord of Brederode and Baron of Holland, Isabeau who married Pierre of Henin-Lietard Lord of Bossu and Great Baron of Hainaut, and Jeanne of Esclaibes who married Philippe of Bourbon, Lord of Ducing.