Manji was born in Toronto, Canada where his Indian parents had immigrated to from Tanzania. His family is Ismaili Muslim, and he states that his religion is very important to him in life. He was raised in Calgary, Alberta, and went to Crescent Heights High School. He later moved to the US where he attended the American Musical and Dramatic Academy. Manji played small parts in various films and television shows with recurring roles in Privileged, Better Off Ted and 24. In 2010, he auditioned for the role of Gupta on the NBC comedy Outsourced. Although he lost the part to Parvesh Cheena, the producers decided to cast him as the scheming assistant manager Rajiv. Manji resides in Studio City, California, with his wife and two children.