Singer Shawn Mendes, best known for his songs "Stitches," "Mercy," "In My Blood" and "Lost in Japan," turns 25 on Tuesday. Shawn Mendes performs on the court in Arthur Ashe Stadium in New York City on August 23, 2014. Mendes performs on stage during Y100's Jingle Ball in Sunrise, Fla., on December 21, 2014.