The Battle of Princeton (January 3, 1777) was a battle in which General George Washington's revolutionary forces defeated British forces near Princeton, New Jersey.

On the night of January 2, 1777 George Washington, Commander-in-Chief of the Continental Army was able to repulse a British attack due to the British's vastly inferior numbers and cannon at the Battle of the Assunpink Creek in Trenton. That night, he evacuated his position, circled around General Lord Cornwallis' army, and went to attack the British garrison at Princeton. Brigadier General Hugh Mercer of the Continental Army, clashed with two regiments under the command of Lieutenant Colonel Charles Mawhood of the British Army. Mercer and his troops were overrun and Washington sent some militia under Brigadier General John Cadwalader to help him. The militia, on seeing the flight of Mercer's men, also began to flee. Washington rode up with reinforcements and rallied the fleeing militia. He then led the attack on Mawhood's troops, driving them back. Mawhood gave the order to retreat and most of the troops tried to flee to Cornwallis in Trenton.

In Princeton itself, Brigadier General John Sullivan encouraged some British troops who had taken refuge in Nassau Hall to surrender, ending the battle. After the battle, Washington moved his army to Morristown, and with their third defeat in 10 days, the British evacuated southern New Jersey. With the victory at Princeton, morale rose in the ranks and more men began to enlist in the army. The battle (while considered minor by British standards) was the last major action of Washington's winter New Jersey campaign.

The site of the battle is now Princeton Battlefield State Park.