As the third son, of James Harington, he did not inherit a great estate.
He built up one for himself, acquiring by his first marriage the manor of Gunthorpe, Rutland, by an indenture dated 19 Feb. 1596, the manor of Ridlington, Rutland from his elder brother, and perhaps at the same time, Knossington manor and Ouston rectory, Leicestershire. He also purchased the Gloucestershire manors of Thornbury Park and Oldebury, and gained the manors of Sugworth, Berkshire and Merton, Oxfordshire, through his second marriage.
Early in 1603 he travelled north with his brother John Harington to meet the new King, who knighted him at Grimston in Yorkshire. He was among the first baronets in 1611, paying a first instalment of £360. He died 2 Feb. 1614 and was buried at Ridlington.
Having assured his principal estates to his son Edward, he bequeathed a life interest in Thornbury and Morton to his wife, together with household stuff. He provided annuities for his wife and four of his younger sons, and left Gunthorpe, Knossington, Oldebury and a few small properties, in all worth £10,000, to his executors, his sons Edward and Sapcote, to pay his debts and legacies. These included £2,000 to one daughter, £1,000 to another, £500 to his second son, and £1,500 to his five youngest sons. He left a colt to his nephew Lord Harington and nominated him supervisor of the will.