Sir Peter Osborne (1584 – 14 April 1653), of Chicksands in Bedfordshire, was an English administrator and Member of Parliament, who was Royal Governor of Guernsey during the English Civil War.
Osborne was the eldest son of Sir John Osborne (1552–1628) and grandson of Peter Osborne (1521–1592), who had been Keeper of the Privy Purse to King Edward VI, and who had been granted the office of Lord Treasurer's Remembrancer to himself and his heirs. Francis Osborne, the well-known writer, was Sir Peter's younger brother. Sir Peter was knighted in 1611, and married Dorothy Danvers. Through the influence of her brother, the Earl of Danby, he was appointed Lieutenant-Governor of Guernsey in 1621 with a reversion on the governorship in the event of Danby's death. He also served in James I's fourth and last parliament (the Happy Parliament in 1624) and Charles I's first parliament (the Useless Parliament in 1625), representing Corfe Castle, and after his father's death in 1628 also inherited his lucrative position in the Exchequer.
On Guernsey, Sir Peter was active with his brother-in-law in reinforcing the island against the threat of invasion from France; however the cost of these soldiers fell on the islanders, occasioning considerable unrest, to which Osborne reacted by attempting to impose martial law in 1628. Parry noted that
He took no pains to make himself loved by the inhabitants of Guernsey. He disliked and distrusted their religious and political principles, and expressed his opinions openly.