Kunal's father is an accountant while his mother is an interior designer.
In 2003, Kunal won the Mark Twain Acting Award at the American College Theater Festival for his performance in The Rose Tattoo.
Kunal was one of the writers of the critically-acclaimed play Cotton Candy which is staged in New Delhi, India.
He was a member of his school's badminton team and played in state competitions in North India.
His name means "one who sees beauty in everything".
His guest appearance on NCIS as a terrorist was his first-ever acting job on television.
Before making it on television, Nayyar studied theater for seven years.
Kunal lives in Los Angeles, California.
Kunal: The circle that I grew up in is very different from what you call a traditional Indian family. My parents are like, 'Yeah, go act!' and all Bohemian, and they're smoking cigarettes, which is something you very rarely see. That's maybe 10 percent of India and the rest of it is very conservative.
Kunal: (comparing himself to his character on "The Big Bang Theory) I also have a lot of nerdy elements in me and at the same time I act as a geek like him. I love playing video games and just like him I also like a lot of epic stuff.
Kunal: I always wanted to do acting, but could never find the right platform in India. While studying in the US, I found that there are a lot of opportunities for me to learn acting and that is how I got my bachelors in marketing and my diploma in acting.
Kunal: Primal human nature is very funny. If I see someone get really angry, and in their anger throw something. It's pretty funny. Or someone trips and falls. Or someone farts and burps.
Kunal: (on the success of "The Big Bang Theory") You have to take your entire life one day at a time. I'm trying to soak it all in and enjoy it.
Kunal: When I actually started acting in college, I just fell in love with the entire art form. The thrill of being in front of an audience...they're breathing with you, they're laughing with you, they're crying with you, so that's a thrill I didn't get in any other field.
Kunal: (on the film he is writing; 2008 interview) The film is about an Indian guy going to America. There he looks for the three basic necessities in a man's life: work, love and friendship. The story is very much related to my life.
Kunal: With sitcoms you are playing to the audience that is watching you as well as the cameras and I am so used to doing that from my stage work.