Sir Henry Clinton's birth date is unknown, but it was probably sometime in 1738. His father was Admiral George Clinton, who later became governor of New York.

Sir Henry Clinton began his military career in the New York militia because his father was governor of that colony. He became a lieutenant in the Coldstream Guards when he was only thirteen years old. He served in Germany during the Seven Years' War and rose to the rank of major general in 1772. Clinton rose to the rank of Major General in 1772 and served in Parliament in 1772 and 1774.

When the American Revolutionary War broke out, Clinton was sent to Boston and in 1775 became the hero in the Battle of Bunker Hill. His actions at Bunker Hill earned him a promotion to Second in Command to General William Howe, the British Commander In Chief. Again in the Battle of Long Island in 1776 he became a hero and was made a Lieutenant General and knighted.

In 1776 after he led the unsuccessful assault of the Continental Army at Sullivans Island at Charleston, South Carolina, he was credited with the capture of Newport, Rhode Island. When General Howe resigned his command in 1778, Clinton was named his successor.

As Commander In Chief the first thing he did was to move his headquarters from Philadelphia to New York. In 1779, he started to concentrate on the soutehrn colonies. With Major General Charles Cornwallis, the British were able to recapture Charleston in 1780. General Clinton and Major General Cornwallis did not get along and debated constantly. Some scholars feel this is why Major General Cornwallis surrendered so easily at the Battle of Yorktown.

In 1781 General Clinton resigned and returned to England where he wrote his biography to explain his actions in the war. In 1790 he reentered the House of Commons.

In 1794 was appointed governor of Gibraltar, but died at the age of about 57 in Cornwall, England on December 23, 1795 before assuming the position.