Mortimer was taught art by his father and later he attended the Art Students League of New York. He was part of the Canadian Army during World War II, but returned home in 1943. He died in 1998 at the age of 79.
Win Mortimer was a professional illustrator and comic book artist. He first worked was as a poster designer until he started working for DC Comics on titles like Detective Comics, World's Finest, Superman and many other classic Golden Age titles. Some of his most notables contributions are his works on the title Star-Spangled Comics, when Robin became the main feature and the official introduction of the Batboat in Detective Comics #110
- Win Mortimer's Images as a Penciler
- Win Mortimer's Images as an Inker
- Win Mortimer's Images as a Cover Artist
- Mortimer is a 2006 inductee into the Canadian comics' creators Joe Shuster Hall of Fame.