A statue of a lion standing upon a stone-block pedestal surmounts the hill. Jean-Louis Van Geel (1787–1852) sculpted the model lion, which closely resembles the 16th-century Medici lions. The lion is the heraldic beast on the personal coat of arms of the monarch of The Netherlands, and symbolizes courage.

Its right front paw is upon a sphere, signifying global victory. The statue weighs 28 tonnes (31 tons), has a height of 4.45 m (14.6 ft) and a length of 4.5 m (14.8 ft). William Cockerill's iron foundry in Liège cast the lion, in sections; a canal barge brought those pieces to Brussels; from there, heavy horse-drays drew the parts to Mont-St-Jean, a low ridge south of Waterloo.

There is a legend that the foundry melted down brass from cannons that the French had left on the battlefield, in order to cast the metal lion. In reality, the foundry made nine separate partial casts in iron and assembled those components into one statue at the monument site.