Thomas Lynch, Jr. (August 5, 1749 - about 1779), was a signer of the United States Declaration of Independence as a representative of South Carolina.

He was born in South Carolina and educated at Cambridge University in England. He studied law in London, returning to America in 1772. He became a company commander in the South Carolina regiment in 1775 and was elected to the Continental Congress. He was taken ill at the end of 1776 and he sailed, with his wife, for the West Indies. Their ship disappeared at sea.