Following his father's death and his mother's remarriage to Sir William St Loe he and his elder brother Henry were sent to Eton.

[1] He then entered Clare College, Cambridge in 1567,[2] around the time of his mother's marriage to George Talbot, 6th Earl of Shrewsbury, and was admitted to Gray's Inn in 1572 to complete his education.

[1] By 1584 his mother had purchased land for him worth £15,900 and his standing as a justice of the peace in Derbyshire meant that he was named of the quorum.

[1] He was created Earl of Devonshire on 7 August 1618, while the court was staying at the Bishop of Salisbury's palace;[5] he was reported to have paid £10,000 for the title.

[1] They had three sons and three daughters, including: Cavendish's second wife was Elizabeth, daughter of Edward Boughton of Couston, Warwickshire, widow of Sir Richard Wortley of Wortley, Yorkshire,[1] by whom he had a son, John, who was made a knight of the Bath when Prince Charles was created Prince of Wales in 1618.