At 10:30 on 19 June General Grouchy, still following his orders, defeated General Thielemann at Wavre and withdrew in good order — though at the cost of 33,000 French troops that never reached the Waterloo battlefield. Wellington sent his official dispatch describing the battle to England on 19 June 1815; it arrived in London on 21 June 1815 and was published as a London Gazette Extraordinary on 22 June. Wellington, Blücher and other Coalition forces advanced upon Paris.

After his troops fell back, Napoleon fled to Paris following his defeat, arriving at 5:30 am on 21 June. Napoleon wrote to his brother and regent in Paris, Joseph, believing that he could still raise an army to fight back the Anglo-Prussian forces while fleeing from the Waterloo battlefield. Napoleon believed he could rally French supporters to his cause and call upon conscripts to hold off invading forces until General Grouchy's army could reinforce him in Paris. However, following defeat at Waterloo, Napoleon's support from the French public and his own army waned, including by General Ney, who believed that Paris would fall if Napoleon remained in power.

Napoleon announced his second abdication on 24 June 1815. In the final skirmish of the Napoleonic Wars, Marshal Davout, Napoleon's minister of war, was defeated by Blücher at Issy on 3 July 1815. Allegedly, Napoleon tried to escape to North America, but the Royal Navy was blockading French ports to forestall such a move. He finally surrendered to Captain Frederick Maitland of HMS Bellerophon on 15 July. Louis XVIII was restored to the throne of France and Napoleon was exiled to Saint Helena, where he died in 1821. The Treaty of Paris was signed on 20 November 1815.