Born William Gower, he was the second son of Sir Thomas Gower, 2nd Baronet and Frances, daughter and coheir of John Leveson. He added the surname Leveson to his own in 1668, when he inherited the Trentham and Lilleshall estates of his maternal great-uncle, Sir Richard Leveson. Leveson-Gower married Lady Jane Granville (the eldest daughter of the 1st Earl of Bath) and they had five children:
