Hugh Hamilton, 1st Viscount Glenawly (c. 1600–1678), also 1st Baron of Deserf in Sweden, was a soldier in Swedish and English service.
He came from a family that descended from the Hamiltons of Dalserf, a cadet branch of the House of Hamilton. The progenitor of the Dalserf branch, David Hamilton of Dalserf, was son of John Hamilton of Cadzow (died 1402), and uncle to, James Hamilton, 1st Lord Hamilton. Hugh's father had moved from Scotland to Ireland in c 1604. The family had obtained Monea and Ballygawley in Tyrone-Fermanagh and Hugh's father had Monea castle built in their hereditary lands in c 1618, in Hugh's adolescence. Hugh's parents were Malcolm Hamilton, the anglican archbishop of Cashel since 1623, and his first wife lady Mary Willkie of Sachtonhill.
Hugh (also known as Hugo in Swedish), who mentions himself being originally a third son and with poor prospects of inheritance, moved from Ireland to Sweden and took part in Thirty Years War. He had a regiment recruited from British Isles and led them in Germany. In Swedish service, he soon rose to be colonel. He received properties Ljung and Slefringe in Östergötland.
In c. 1637 Hugh Hamilton married, for first time. The bride was Margaret Forratt (d 1653), of Scots family, and widow of colonel and ambassador baron James Spens (Jakob), 1st Friherre of Orreholmen, who had died 1632, and been in Swedish service. Friherrinna Margaret had two sons of her first marriage (major, baron Axel Spens of Orreholmen, 1626–56, and colonel, baron Jakob Spens of Orreholmen, 1627–65), who thus became Hugh's stepsons. In his first marriage, lord Hugh got one surviving child, his daughter baroness Bridget Margaret Hamilton af Deserf, who in 1659 married baron Kustaa Adolf Skytte of Tuutarhovi.