Popular Indian singer KK was born as Krishnakumar Kunnath in Delhi. He completed his schooling from Mount St. Mary School and then earned his graduation degree from Kirori Mal College, Delhi University in Commerce. After college, he worked as a marketing executive for eight months in the hotel industry. 

He began his singing career in the year 1994, when he moved to Mumbai. He got his first break in the music industry after he met and gave a demo tape to musicians Louis Banks, Ranjit Barot and Lesle Lewis. He got his first jingle through Lesle Lewis, who he considers his mentor in the music industry. KK started by singing jingles (3,500 jingles in 11 Indian languages till date) for TV advertisements before he got a break as a playback singer.  

After being introduced to A.R. Rahman by mentor Lesle Lewis, KK got the opportunity to sing for the music maestro’s famous hits ‘College Styley’ and ‘Hello Dr’ from Kadir's ‘Kadhal Desam’ (1996). After this, he also lent his voice to the famous ‘Strawberry Kannae’ from AVM Productions's musical film Minsara Kanavu (1997). 

KK’s Bollywood break with ‘Tadap Tadap Ke Is Dil Se’ from blockbuster film Hum Dil De Chuke Sanam  (1999) got him instant recognition. However, it is a lesser known fact that before this, he had sung a small portion of the song ‘Chod Aaye Hum’ from Gulzar's Maachis (1996). 

KK has over 500 songs in Hindi and more than 200 songs in Telugu, Bengali, Tamil, Kannada and Malayalam languages to his name. Leading Indian music composers like Rajesh Roshan, Ilayaraja, R. D. Burman, Vishal Bhardwaj, Ismail Darbar, Himesh Reshammiya, Anu Malik, Lesle Lewis, Bappi Lahiri, Anand-Milind, Vishal-Shekhar, Ajay-Atul, Vipin Patwa, Ashok Bhadra, M. M. Keeravani, Vidyasagar, Mani Sharma, A. R. Rahman, Yuvan Shankar Raja, Harris Jayaraj, G. V. Prakash Kumar, Deva, R. P. Patnaik, Devi Sri Prasad, Ramana Gogula, Amit Trivedi, Shankar Ehsaan Loy, Ranjit Barot, Abhishek Ray, Pritam Chakraborty have worked with him. 

However, this playback singer also cut a solo album in 1999, with Sony Music - titled ‘Pal’ with Lesle Lewis as the music composer. The album earned him the prestigious Screen Award as Best Singer. He released his second album ‘Humsafar’ in 2008, which was also well received. 
 
KK has also sung for popular television series like ‘Just Mohabbat’, ‘Shaka Laka Boom Boom’, ‘Kuch Jhuki Si Palkein’, ‘Kavyanjali’, etc. He also played the role of a jury member for the talent hunt show Fame Gurukul. The talented singer also featured on MTV India Coke Studio.