Mark Alt (born October 18, 1991) is an American professional ice hockey defenseman who is currently playing for the San Jose Barracuda in the American Hockey League (AHL).
After his third season of collegiate hockey with the Golden Gophers having scored 39 points in 117 collegiate games, Alt signed a three-year entry level contract with the Philadelphia Flyers on April 7, 2013. He immediately joined the Flyers American Hockey League primary affiliate, the Adirondack Phantoms on an amateur try-out contract to finish the 2012–13 regular season. Appearing in 6 games with the Phantoms, Alt earned praise from veteran NHL and blueline partner in Andreas Lilja.