Alka Yagnik is classically trained and has been one of the leading playback singers in Bollywood since the late 1980's. She began singing bhajans for Calcutta Radio at the age of six. Her first song was for the film Payal Ki Jhankaar in (1979), followed by Laawaris (1981) with the hit song "Mere Angene Mein", followed by the film Hamari Bahu Alka (1982). She got her big break with the song "Ek Do Teen" from the film Tezaab (1988). The song turned her into a star overnight and went on to become a pop hit, also winning her a Filmfare Best Female Playback Award. Qayamat Se Qayamat Tak was also a career maker for her, as she along with Udit Narayan became household names.

She has sung in many languages other than Hindi, including Gujarati, Oriya, Assamese, Nepali, Rajasthani, Bengali, Bhojpuri, Punjabi, Marathi, Telugu, Tamil, and Malayalam. In addition, she has been the number one choice for film songs due to the versatility of her voice, in which more film heroines have requested her voice be dubbed over their performance. Other than Nadeem-Shravan,she has worked with many other Indian composers such as, Kalyanji-Anandji, Laxmikant-Pyarelal, A R Rahman, Anand-Milind, Viju Shah, Himesh Reshammiya, Shankar-Eshaan-Loy, and others. Additionally, she is the personal favorite of composers Laxmikant-Pyarelal, Anu Malik, Rakesh Roshan, Nadeem-Shravan, and Jatin-Lalit, for whom she is the first choice for their compositions.

She shares the title with Asha Bhonsle for the most number of Filmfare Awards won (7) by a single female playback singer. Alka has also been the judge of various Sa Re Ga Ma Pa Challenge shows, and Star Voice of India, both singing competition shows, in which children or adults of various age groups compete with one another to win the award for best vocals. In addition to this, her song "Chamma Chamma" from China Gate was featured in the song "Hindi Sad Diamonds" from the soundtrack of the film Moulin Rouge!.