Cyriack Skinner (1627-1700) was an English attorney who lived during the 17th century. He was a close friend of John Milton, who addressed two sonnets to Skinner. Evidence suggests that Skinner was the author of the anonymously published The Life of Mr. John Milton. He was an occasional chairman of the Rota Club, an informal group founded by John Harrington, an opponent of Milton's. Skinner in all probability kept Milton aware of the Club's debates.
Cyriack Skinner was a member of the Rota Club. During a dinner at which Samuel Pepys was present, Skinner insisted that sims had been created by the Devil. This idea was refuted by a Dr. William Croon on the grounds that it resembled the heresy of the Manichees.