George Hamilton, 4th Baron Hamilton of Strabane (died 1668) was the younger son of Claud Hamilton, 2nd Baron Hamilton of Strabane. He succeeded to the title in 1655 when his brother drowned while bathing in the River Mourne. After the Restoration, he obtained the return of the family lands around Strabane, which had been confiscated by the Parliamentarians in 1650.

George was born in 1636 or 1637, probably at Strabane Castle. He was the younger son of Claude Hamilton and his wife Jean Gordon. His father was the 2nd Baron Hamilton of Strabane and a member of the Strabane cadet branch of the Abercorns. The lords of Strabane owned much land around Strabane and Baronscourt in County Tyrone.

George's mother was the fourth daughter of George Gordon, 1st Marquess of Huntly in Scotland. His parents were both Catholic. They married in 1632. He was one of four siblings, who are listed in his father's article.

In 1638, while George was still an infant, his father died and was buried in the church of Leckpatrick near Strabane. His older brother James succeeded as the 3rd Baron Hamilton of Strabane as a young child. His mother ran the family estate and they continued to live in the Castle of Strabane.

In 1641, when George was about four years old, the Irish Rebellion broke out. The rebel leader Phelim O'Neill captured and burned Strabane Castle and took him, together with his mother and siblings, as prisoners to Kinard, his usual place of residence. Phelim released his prisoners after some days and sent them to Sir George Hamilton, one of George's uncles.

In 1649, when George was about 12, during the Irish Confederate Wars, Strabane Castle was attacked again, this time by Robert Monro and his Covenanter army. The castle was relieved by Phelim O'Neill, its previous attacker. Phelim married George's mother in November. Phelim became his stepfather and his half-brother Gordon O'Neill was born in due course.

In 1649 Oliver Cromwell invaded Ireland with the Parliamentarian forces. In July 1650, in the Siege of Charlemont, his brother and his stepfather defended Charlemont Fort with remnants of the Confederate Ulster army against a Parliamentarian army under Charles Coote. Having resisted several attacks, the fort finally surrendered to Coote on terms in August and the garrison was allowed to march away. In July 1650, the family's lands were confiscated by the Parliamentarians. In 1652 Phelim O'Neill was captured. He was tried and convicted for treason in October and executed.

In June 1655 his brother, James, drowned in the River Mourne at Ballyfathen, aged about 22. His brother had never married and George succeeded him as the 4th Baron Hamilton of Strabane. He is usually called Lord Strabane rather than Lord Hamilton to avoid confusion with the Lords Hamilton of the senior, Scottish, branch of the family.^{[citation needed]}