Rosato got his start as a sketch comedian for the Canadian show SCTV in 1980. From there, he joined the cast of Saturday Night Live in 1981. Rosato, born in Naples, Italy, became the first cast member born outside of North America. He only stayed on SNL for the 1981-82 season. In 1985, he took on the role of Arthur Morelli in the Canadian police procedural Night Heat, and played the character until the show ended in 1989.
It was in the role of Luigi where Rosato hit his stride. He was cast as Mario’s younger brother, opposite Walter Boone, in the 1990 series The Adventures of Super Mario Bros. 3. The show, loosely based on the Super Mario Bros. video game franchise, saw Luigi, Mario, Toad, and Princess Toadstool fighting off King Koopa’s attempts to overthrow the Mushroom Kingdom. Rosato voiced Luigi for each of the 26 episodes.
He reprised his role as Luigi in the 1991 animated series Super Mario World. Although the show shared the same name as the iconic side-scroller, Super Mario World took massive liberties with the subject matter. In a departure from The Adventures of Super Mario Bros. 3, Super Mario World was a musical-comedy series comprised of 13 episode, each of which was 10 minutes long.
After voicing Luigi, Rosato went on to voice roles in The Busy World of Richard Scarry, The Adventures of Sam & Max: Freelance Police, and Resident Evil 3: Nemesis, a video game. In all, Rosato had 92 acting credits to his name, both big and small, and across wide-ranging forms and genres.