The 1783 treaty that formally ended the American Revolutionary War was the Treaty of Paris.
Representatives of Great Britain and the United States signed the treaty in Paris on September 3, 1783. Its terms ended the war between the two countries and recognized the Thirteen Colonies as free, sovereign, and independent states. The agreement also established boundaries for the new United States and addressed several other postwar issues.
Peace negotiations had begun in Paris in April 1782, after the Continental Army’s victory at Yorktown and the resulting crisis for the British war effort. The Continental Congress ratified the treaty on January 14, 1784. The final ratification documents were exchanged later that year, completing the formal process.
A common mix-up is the phrase Peace of Paris, which refers to the wider group of agreements signed in 1783. Britain also made separate treaties with France, Spain, and the Dutch Republic. The Treaty of Paris specifically refers to the agreement between Great Britain and the United States, making it the precise answer to this question.