An alumnus of National School of Drama, K. K. Raina is an award-winning scriptwriter, who is also known for playing character roles. He made his acting debut in the early 1980s, K. K. Raina was first seen in the movie Vijeta, following which he was seen in popular movies such as Gandhi, Trikal, Damini, Ghatak: Lethal, Lakshya, Rang De Basanti, Delhi-6, Tanu Weds Manu, and Bhaag Milkha Bhaag among many others. While he actively pursued his acting career, he was also credited as the associate screenplay writer of Ghatak in 1996. For his dialogue writing for China Gate, he won the Filmfare Award for Best Dialogue. In 2017, the actor and screenwriter was seen in the Rajkummar Rao and Kriti Kharbanda-starrer Shaadi Mein Zaroor Aana.