Manji was born in Toronto, Ontario, to Indian parents who immigrated there from Tanzania. His family is Ismaili Muslim of Gujarati Indian descent, and he has said that his religion is very important to him. When Manji was in first grade, he and his family moved to Calgary, Alberta, where he was raised. He graduated from Crescent Heights High School.
Manji's parents wanted him to go to college to earn a degree, but he wanted to be an actor. He attended the University of Alberta, where his sister Rishma was enrolled. The only class he enjoyed there was drama. In 1992 Manji enrolled at the American Musical and Dramatic Academy in New York City.
During the early years of Manji's career, he played small parts in various films and television shows, with recurring roles in Privileged, Better Off Ted and 24. In 2010 Manji auditioned for the role of Gupta on the NBC comedy Outsourced. Parvesh Cheena got the part, but the producers cast Manji as the scheming assistant manager Rajiv. Manji appeared in a GEICO commercial as a customer in the checkout aisle who wins the "auction".
|2008||Hannah Montana||Ajay||Episode: "You Never Give Me My Money"|
|2009||The Suite Life on Deck||Swami Banu Kapatu||Episode: "The Mommy and the Swami"|
|2012||Shake It Up||John||Episode: "Whodunit Up?"|
|2013–2014||Dog with a Blog||Dr. Young||2 episodes|
|2015||The Thundermans||Babu Ouch||Episode: "Phoebe vs Max: The Sequel"|
|2015–2016||Bella and the Bulldogs||Mr. Matoo||2 episodes|
|2019-Present||Sydney to the Max||Vice Principal Virmani||Recurring Role|
- Manji lives in Studio City, California, with his wife and three children.