- Named after his grandfather Raj Kapoor, whose first name is Ranbir Raj.
- Sustained an inch-long cut on his right cheek while rushing to the lavatory and falling face-first on the pot when he was a kid.
- First worked as an assistant to his father who directed the film Aa Ab Laut Chalen (1999), right after he appeared for his ICSE Board exams.
- Worked as an assistant director for Sanjay Leela Bhansali's movie Black (2005), which bagged eleven Filmfare Awards.
- Debuted with the movie Saawariya (2007). The role won him the Filmfare Best Male Debut Award.
- Worked in Zoya Akhtar's short film Because My World Is Not The Same (2012) to help spread breast cancer awareness.
- Started a production house Picture Shuru Productions in partnership with Anurag Basu in 2013.
- Confessed to having a drinking problem in 2016.
- A nasal deviated septum keeps him breathing from his mouth and makes him talk and eat fast.
- Works as a goodwill ambassador for Shabana Azmi's NGO Mijwan Welfare Society, which supports child empowerment.