Tabu admitted that in all the years she had lived in India, she had never seen the Taj Mahal. The scene in the movie where the family goes to see the Taj Mahal was her first time seeing famous tomb.
Mira Nair originally wanted Abhishek Bachchan to play the part of Gogol. She changed her mind, because she wanted someone who would seem to the audience to have been raised in the US. She cast Kal Penn, as he was very keen to do the role, and also because her son was advocating for her to cast him.
Many of the "New York" interiors, such as the disco, Moushimi's apartment, the honeymoon suite, etc., were actually filmed in Calcutta to save costs.
In the ending credits of the movie Kal Penn is listed twice. He is credited as Kal Penn playing Gogol and Kalpen Modi playing Nikhil.
The Lupita Nyong'o who is credited as a post-production intern in the Editorial Department is the same person who went on to become an Academy-Award-winning actress in such movies as 12 Years a Slave, Black Panther, Us, and the Star Wars series. Nyong'o would later star in Queen of Katwe, which Mira Nair also directed. The year before interning on The Namesake, she had also served as a production runner on the Kenya set of "The Constant Gardener."