Ted Williams
Ted Williams, a famous Red Sox player, actually had a career outside the baseball diamond. He enlisted in the US Marine Corps during World War II and served for about three years. Additionally, during the Korean War, he flew as a combat aviator. In his time there, he flew 39 different combat missions. Once he came back, he was named the "Comeback Player of the Year."
Prince Andrew
Who wouldn't want a member of royalty in their platoon? The Duke of York served in the English military as a helicopter pilot for a few years. Additionally, until 1986, the Duke served on the HMS Brazen. He was deployed in the Mediterranean Sea and fought in the Falklands War. He was described by a Commander as "an excellent pilot and a very promising officer."