John Jay Almy (April 21, 1815 – May 16, 1895) was a U.S. Navy Rear-Admiral, who held the record for the longest period of seagoing service (27 years, 10 months). In the Mexican War, he took part in the capture of Vera Cruz, and in the Civil War, he captured four blockade-runners and destroyed four others. As a Rear-Admiral during a violent revolt in Panama in 1873, he was able to protect American and European property, earning official thanks from many nations.