Capt. John Alden Sr. (c.1599–1687) was a crew member on the historic 1620 voyage of the Pilgrim ship Mayflower. Rather than return to England with the ship, he stayed at what became Plymouth Colony. He was hired in Southampton, England, as the ship's cooper, responsible for maintaining the ship's barrels. He was a signatory to the Mayflower Compact. He married fellow Mayflower passenger Priscilla Mullins, whose entire family perished in the first winter. He served in a number of important government positions such as Assistant Governor, Duxbury Deputy to the General Court of Plymouth, Captain Myles Standish's Duxbury militia company, a member of the Council of War, Treasurer of Plymouth Colony, and Commissioner to Yarmouth.
His origins are largely subject to speculation, but it is currently believed that he was from the Alden family of Harwich in Essex, England. Harwich is an ancient North Sea port, northeast of London, which was the homeport of the Pilgrim ship Mayflower and home of its captain, Christopher Jones. The Alden family of Harwich had distant connections to Jones, residing there in the 17th century and possibly related to him by marriage. The only certainty about his English background were Bradford's words that Alden “was hired for a cooper, (barrel maker) at Southampton, where the ship victuled; and being a hopeful young man, was much desired, but left to his liking to go or stay when he came here; but he stayed, and maryed here.” Author Charles Banks states that the employment of Alden “at Southampton” does not necessarily mean that he was a resident of the seaport and may have only been there to work temporarily when the Mayflower arrived. Banks notes a young John Alden about the same age as the Mayflower passenger was a seafarer in Harwich in the early 17th century,