K.K.Singh started his careeras Additional dialogue writer to Jainendra Jain in Raj Kapoor's movie, Prem Rog (1982). He impressed Raj Kapoor and got an opportunity to write the screenplay for Ram Teri Ganga Maili (1985) along with V.P.Sathe and Jyoti Swaroop. K. K. Singh, famous for hard hitting dialogues in action drama and social movies had numerous hits in movies like Sansar (1987), Tridev (1989), Ek Rishtaa: The Bond Of Love (2001). His last movie was Jeevan Sathi (2006). He wrote dialogues for actors like Raaj Kumar, Amitabh Bachchan, Dharmendra, Nana Patekar, Sanjay Dutt and Sunny Deol.
He wrote lyrics for Rambhoomi (1991) with music by Laxmikant Pyarelal. He even produced and directed a movie Veergati (1995), starring Salman Khan. He even trying his hand in acting for a movie, Sham Ghanasham (1998) by Subhash Ghai.
He won Star Screen Award for Best Story and Best Dialogues for Krantiveer (1994). He passed away on October 30, 2011 in Mumbai.