Kedarnath Bhattacharya (born 23 September 1957), better known as Kumar Sanu, is an Indian playback singer who mainly sings for Hindi and Bengali films, and is popular for rendering his voice in Bollywood movies of the 1990s and early 2000s. He was awarded the Filmfare Best Male Playback Singer Award for five consecutive years. In 2009, the Government of India awarded him the Padma Shri, India's fourth-highest civilian honour, in recognition of his achievements. Sanu notably holds the Guinness World Record for most songs recorded by a singer in 24 hours with 28.
Sanu's father, Pashupati Bhattacharya, was a vocalist and composer. The two and Sanu's elder sister lived in the Sinthee area of Calcutta (now Kolkata) near Biswanath Park. Bhattacharya trained under renowned musicians of the region, Jiban Upadhyay and Bishodeb Chattopadhyay, the former of the Badal Khan and Jamruddin gharana. Classically trained, he sang for the Dhaka radio alongside Jagan Mitra and Sudhirlal Chakrabarty. Sanu said of him, "He was a master of thumri, khayal and bhajans. Only my elder sister Jayshree Mukherjee, was trained by him. The rest of us would listen to him entranced and we learnt a lot from that."
In 1989, Jagjit Singh introduced Kumar Sanu to Kalyanji-Anandji at their residence Vimal Bunglows in Mumbai. On their suggestion, he changed his name from "Kedarnath Bhattacharya" to "Kumar Sanu" because his voice and singing style were much influenced by Kishore Kumar. Anandji shared this story on the show Jeena Isi Ka Naam Hai, hosted by Farooq Sheikh. Sanu then relocated to Mumbai, where Kalyanji-Anandji gave him a chance to sing in the film Jaadugar.
For the 1990 film Aashiqui, music directors Nadeem-Shravan got Sanu to sing all but one of the songs. He won the first of his record five consecutive Filmfare Awards as Best Male Playback Singer. His next Filmfare Awards came for songs in the movies Saajan (1991), Deewana (1992), Baazigar (1993) and 1942: A Love Story (1994). He won 5 back to back Filmfare awards for singing, between 1990 and 1994.
Kumar Sanu got his major break when Gulshan Kumar with music directors Nadeem and Shravan gave him chance to sing most of the songs of movie Aashiqui (1990), songs were recorded earlier for an album and later movie was made around the songs. The movie as well as the songs were a grand success. Thereafter, they worked together in many films, including Saajan (1991), Phool Aur Kaante (1991), Dil Hai Ki Manta Nahin (1991), Sadak (1991), Pyaar Ka Saaya (1991), Saathi (1991), Deewana (1992), Dil Ka Kya Kasoor (1992), Jaan Tere Naam (1992), Sapne Sajan Ke (1992),Anaam (1992), Paayal (1992), Panaah (1992), Bekhudi (1992), Kal Ki Awaaz (1992), Hum Hain Rahi Pyar Ke (1993), Sainik (1993), Junoon (1993), Waqt Hamara Hai (1993), Rang (1993), Sangraam (1993), Shreeman Aashiq (1993), Dhartiputra (1993), Dilwale (1994), Aatish (1994), Ekka Raja Rani (1994), Saajan Ka Ghar (1994), Andolan (1995), Barsaat (1995), Anokha Andaaz (1995), Saajan Ki Baahon Mein (1995), Zamaana Deewana (1995), Raja Hindustani (1996), Agnisakshi (1996), Saajan Chale Sasural (1996), Pardes (1997), Naseeb (1997), Aa Ab Laut Chalen (1999), Sirf Tum (1999), Dhadkan (2000), Kasoor (2001), Hum Ho Gaye Aapke (2001), Ek Rishtaa: The Bond of Love (2001), Yeh Dil Aashiqanaa (2002), Ansh (2002), Haan Maine Bhi Pyaar Kiya (2002), Dil Hai Tumhaara (2002), Tum Se Achcha Kaun Hai (2002), Dil Ka Rishta (2003), Qayamat (2003) Footpath (2003), Andaaz (2003), Barsaat (2005), And Mere Jeevan Saathi (2006), . He has sung his most songs for them (293 songs).
Sanu has sung songs of various genres with Anu Malik. It was Malik who made Sanu sing his first western-style song "Yeh Kaali Kaali Aankhe", from the film Baazigar (1993). Some other achievements of the combo are Chamatkar (1992), Phir Teri Kahani Yaad Aayee (1993), Sir (1993), Imtihaan (1994), Vijaypath (1994), Main Khiladi Tu Anari (1994), Naaraaz (1994), Yaar Gaddar (1994), Hum Hain Bemisaal (1994), Aa Gale Lag Jaa (1994), Naajayaz (1995), Gundaraj (1995), Hulchul (1995), Akele Hum Akele Tum (1995), Diljale (1996), Sapoot (1996), Daraar (1996), Chaahat (1996), Virasat (1997), Hamesha (1997), Dil Kitna Nadaan Hai (1997), Judwaa (1997), Tamanna (1997), Duplicate (1998), Kareeb (1998), Soldier (1998), Iski Topi Uske Sarr (1998), Hum To Mohabbat Karega (2000), Ajnabee (2001), Aan: Men at Work (2003), Ishq Vishq (2003), Fida (2004) and No Entry (2005). In 2015, they were again back with songs in Dum Laga Ke Haisha.
Sanu started his work with Jatin Lalit on the 1992 film Khiladi. From then on he provided his voice for hit movies including Raju Ban Gaya Gentleman (1992), Kabhi Haan Kabhi Naa (1993), Dilwale Dulhania Le Jayenge (1995), Khamoshi (1996), Yes Boss (1997), Jab Pyaar Kisise Hota Hai (1998), Kuch Kuch Hota Hai (1998), Pyaar To Hona Hi Tha (1998), Ghulam (1998), Dil Kya Kare (1999), Khubsoorat (1999), Sangharsh (1999), Yeh Hai Mumbai Meri Jaan (1999), Vaastav (1999) and Sarfarosh (1999). He has sung a total of 136 songs for them.
Sanu worked for Himesh Reshammiya, for all title tracks of TV serials which Reshammiya produced. All the title tracks were sung by Sanu, and then in his debut film as a music director, Pyaar Kiya To Darna Kya and further for many other films such as Kurukshetra, Yeh Hai Jalwa, Humraaz, Kahin Pyaar Na Ho Jaaye, Hello Brother, Bandhan, Dulhan Hum Le Jayenge, Jodi No.1, Uljhan, Footpath and Taarzan: The Wonder Car.
Beginning with "Jab Koi Baat Bigad Jaye" in the movie Jurm (1990), Sanu's collaboration with Rajesh Roshan produced one hit after another. Significant movies include Karan Arjun (1995), Sabse Bada Khiladi (1995), Papa Kehte Hai (1996), Dastak (1996), Koyla (1997), Kaho Naa... Pyaar Hai (2000), Kya Kehna (2000), Karobaar: The Business of Love (2000) and Aetbaar (2004).
Sanu has rendered his voice for some of Viju Shah's greatest compositions. Vishwatma (1992), Mohra (1994), Tere Mere Sapne (1996), Gupt (1997), Aar Ya Paar (1997), Beti No. 1 (1999), Bulandi (2000), Pyaar Ishq Aur Mohabbat (2001) and Kasam (2001) are some of their notable albums.
Sanu has recorded over 150 songs with Anand-Milind. Breaking away from his romantic image, he has sung peppy numbers for the duo, his most famous ones being for actor Govinda. He worked with the duo and successfully delivered hits such as Jigar (1992), Raja Babu (1994), Suhaag (1994), Jai Kishan (1994), Elaan (1994), Coolie No 1 (1995), Hero No. 1 (1997), Gair (1998), Chal Mere Bhai (2000), Army (1996), Trinetra, Lootere (1993), Gopi Kishan (1994) and Rakshak (1996).
Kumar Sanu has composed music for various Indian films. Utthaan and Yeh Sunday Kyun Aata Hai are most remarkable among them. Lata Mangeshkar, Asha Bhosle, Kavita Krishnamurthy, Anuradha Paudwal, Sapna Mukherjee, Alka Yagnik, Sonu Nigam, Sadhana Sargam, Sudesh Bhonsle, Shaan, Shreya Ghosal, Hema Sardesai, Sunidhi Chauhan and many more lent their voices for his music. "Yeh Kaisa Utthhan Hai" (sung by Asha Bhosle and Sonu Nigam in two different versions) and "Jisne Sapna Dekha" (sung by Sanu himself) are critically acclaimed.
In 2017, Kumaar Saanu along with Sadhna Sargam sung for the title track of 19s Story based TV Series "Yeh Un Dinon Ki Baat Hain" and also appeared as a part for cameo in it. 
In 2019, Kumaar Saanu made a little singing for the Star Plus's "Kulfi Kumarr Bajewala".
Other than singing and composing music for films, he has also shown interest in producing films. In 2006, he produced his first Hindi film Utthaan.
Currently, he is working with a fellow producer, Rakesh Bhhatia on a new project named Yeh Sunday Kyun Aata Hai. The film is based on the lives of four children who live in the streets of Mumbai and polish shoes at a train station in order to earn their livelihoods. The film will feature Mithun Chakraborty in a leading role. Recently, Sanu sang for a Bangladeshi Bengali film Hason Raja, which was directed by a UK-based filmmaker Ruhul Amin. This movie was never released. He also has composed for some Bengali movies; Amrita and Tobu Aporichito.
Sanu was on the panel of judges on Sony TV for Waar Parriwar, a reality show based on the bringing together of a singing gharana (family of singers) and on Zee Bangla TV in a music reality show called Sa Re Ga Ma Pa - Vishwa Sera.
In 2012, he judged the Zee Bangla musical reality show Sa Re Ga Ma Pa – Gane Gane Tomar Mone. At present, he is one of the judges on the Bengali version of the popular musical reality show Sa Re Ga Ma Pa L'il Champs.
Recently he recorded an album named Hum aur Tum. He also recorded a Spanish song for an album. He has also the record for the most recordings of songs in a single day, 28 songs. popularly he is known for melody king.
Sanu is a trustee and Brand Ambassador of Bishwa Bandhan, a foundation for cerebral palsy.
Work with other singers
Sanu had multiple hit duet numbers with singers Lata Mangeshkar, Asha Bhosle, Anuradha Paudwal, Alka Yagnik, Kavita Krishnamurthy, Sadhana Sargam, Alisha Chinai, Sunidhi Chauhan, Sapna Mukherjee, Poornima, Sapna Awasthi, Shreya Ghoshal, Akriti Kakkar, Monali Thakur, Neha Kakkar, and others. Sanu also multiple duets with his daughter Shannon K, pop singer and songwriter, who has launched her career in the United States in 2017.
Sanu is also credited with the highest number of version songs and male duet hits with the finest singers of 1980s and 1990s. Some of the notable songs are as follows:
He joined the Bharatiya Janata Party in 2004 in a ceremony headed by then Party President Venkaiah Naidu, but he later resigned to concentrate on singing. He rejoined BJP on 2 December 2014, inducted by Amit Shah. 
Kumar Sanu returned to playback singing in 2012. He made a comeback at the urge of composer Sajid-Wajid. Sajid-Wajid gave him "Chammak Challo Chhail Chhabili" - Rowdy Rathore, a wedding song with Shreya Ghoshal. In 2015, Kumar Sanu replaced Lata Mangeshkar as the background voice of Yash Raj Films logo for the film Dum Laga Ke Haisha. This was the first time in YRF's 60-year history that Lata Mangeshkar's voice was replaced.
- Filmfare awards — 1991-1995
- Padma Shri (2009)
- Screen award for Best Male Playback
- 2017: BAIBASUTA Award
- 2016: 8th position on "Google most searched Indian singers in last 10 years"
- 2016: International Bhojpuri Film Awards (IBFA), Dubai – Golden Voice Award
- 2016: Most trusted singer according to "Celebrity / Personality Brand Trust Report: India Study 2016"
- 2015: "Prudent Personality of the Nation" by Parwaz Corporate Today
- 2004: Kala Vedika Awards - "Pride Of India Award", for Promoting Indian Culture Through Indian Music
- 2004: Global Excellence Award
- 2003: Bollywood Music Award For "Best Artist of the Decade"
- 2001: Channel V Award For Best Male Playback for "Chand Sitare" - Kaho Naa... Pyaar Hai
- 2000: Hero Honda Award For Best Playback Singer (Male) for "Aankhon Ki Gustakhiyan" - Hum Dil De Chuke Sanam
- 2000: Kalashree Award For Best Male Playback for "Chaand Sitare" - Kaho Naa... Pyaar Hai
- 2000: Nomination: IIFA Award for Best Male Playback for "Aankhon Ki Gustakhiyaan" - Hum Dil De Chuke Sanam
- 2000: Nomination: MTV Award for "Dil ne yeh" with Udit Narayan and Alka Yagnik
- 1999: Mohammed Rafi Memorial Award for Best Playback Singer For "Aankhon Ki Gustakhiyaan" - Hum Dil De Chuke Sanam
- 1999: Nomination: MTV Award for "Aankhon Ki Gustakhiyaan" With Kavita Krishnamurthy - Hum Dil De Chuke Sanam
- 1999: Zee Gold Awards for "Aankhon Ki Gustakhiyaan" - Hum Dil De Chuke Sanam
- 1999: Kalakar Awards for "Aankhon Ki Gustakhiyaan" - Hum Dil De Chuke Sanam
- 1999: CSR Gold Award for Best Playback Singer "Aankhon ki gustakhiyaan" - Hum Dil De Chuke Sanam
- 1999: Stardust Award for Best Playback Singer For "Aankhon Ki Gustakhiyaan" - Hum Dil De Chuke Sanam
- 1999: Anandalok Awards for Best Playback Singer (Male) Kumar Sanu for Ami Sei Meye
- 1998: Lions' Club Gold Award For Best Playback Singer "Ladki Badi Anjani Hai" - Kuch Kuch Hota Hai
- 1998: Grammy W. Indian
- 1998: Punjabi Kalirangan Award
- 1998: Anandalok Awards For Best Playback Singer (Male) Kumar Sanu for Gane Bhuban Bhoriye Debo
- 1997: BFJA Award for film Lathi
- 1997: Punjabi Kalirangan Award
- 1996: BFJA Award for film Kencho Khurte Keote
- 1995: Deva Award
- 1995: Channel V Award For Best Male Playback "Tujhe Dekha To Yeh Jaana Sanam" - Dilwale Dulhania Le Jayenge
- 1995: Ashirwad Award For Best Male Playback "Ek Ladki Ko Dekha" - 1942: A Love Story
- 1995: Screen Award for Best Male Playback for "Ek Ladki Ko Dekha" - 1942: A Love Story
- 1993: SUMU Award For Best Male Playback Singer in 1993 for Singing Maximum Good Songs
- 1993: SUMU Award For Best Male Playback Singer, in Baazigar