Borlase was the younger son of Sir William Borlase of Marlow who was MP for Wycombe, and his wife Amy Popham, daughter of Sir Francis Popham.
His elder brother was Sir John Borlase, 1st Baronet.
He matriculated at Magdalen Hall, Oxford on 30 April 1635, aged 14, and was a student at Inner Temple in 1637.
[1] Borlase married Joanna Bankes, daughter of Sir John Bankes, Chief Justice of the Common Pleas and his wife Mary Hawtrey; her sister Alice married his brother John.
His daughter Henrietta married firstly Sir Richard Astley, 1st Baronet and secondly in 1690, John Richmond Webb of Biddesden, Wiltshire.