Rich was the eldest son of Robert Rich, 1st Earl of Warwick and his wife Penelope Devereux, Lady Rich, and succeeded to his father's title (Earl of Warwick) in 1619. (A younger brother was Henry Rich, 1st Earl of Holland.) Early developing interest in colonial ventures, he joined the Guinea, New England, and Virginia companies, as well as the Virginia Company's offspring, the Somers Isles Company. Warwick's enterprises involved him in disputes with the British East India Company (1617) and with the Virginia Company, which in 1624 was suppressed as a result of his action. In 1627 he commanded an unsuccessful privateering expedition against the Spaniards.
Warwick's Puritan connections and sympathies gradually estranged him from the court but promoted his association with the New England colonies. In 1628 he indirectly procured the patent for the Massachusetts Bay Colony, and in 1631 he granted the "Saybrook" patent in Connecticut. Forced to resign the presidency of the New England Company in the same year, he continued to manage the Somers Isles Company and Providence Island Company, the latter of which, founded in 1630, administered Old Providence on the Mosquito Coast. Meanwhile, in England, Warwick opposed the forced loan of 1626, the payment of ship money, and Laud's church policy.
His Richneck Plantation was located in what is now the independent city of Newport News, Virginia. The Warwick River, Warwick Towne, Warwick River Shire, and Warwick County, Virginia are all believed named for him, as are Warwick, Rhode Island and Warwick Parish in Bermuda (alias The Somers Isles). The oldest school in Bermuda, Warwick Academy, was built on land in Warwick Parish given by the Earl of Warwick; the school was begun in the 1650s (its early records were lost with those of the Warwick Vestry in a twentieth-century shipwreck), though the school places its founding officially in 1662.
In 1642, following the dismissal of the Earl of Northumberland as Lord High Admiral, Warwick was appointed commander of the fleet by Parliament. In that capacity, in 1648, Warwick retook the 'Castles of the Downs' (at Walmer, Deal, and Sandown) for Parliament, and became Deal Castle's captain 1648-53.