John Ussher (died 1741)
John Ussher (circa 1682 – 1741) was an Irish soldier and Member of Parliament.
On 20 December 1714 he married Mary St George, daughter and heiress of Sir George St George, later Lord St George.
In November 1715 he was elected to the Irish House of Commons for his father-in-law's former constituency of Carrick, sitting until his death. He later also served as Governor of Galway and Vice-Admiral of Connaught.
His son St George Ussher succeeded to his seat in Parliament. He later adopted the surname St George and was created Baron St George. His daughter Olivia married Arthur French and their son Christopher adopted the surname St George in 1774; he was the grandfather of Christopher St George.