From an early age Wells had a love of music and singing and was a member of the Northwestern High School choir. She also sang at local clubs and competed in various talent contests. In 1959, she met Tamla Records chief Berry Gordy's assistant, Robert Bateman, telling him about a song she had written for artist Jackie Wilson. Bateman arranged an audition for Wells and her song with Gordy, and she sang the song for the record producer. Instead of buying the song for Wilson, Gordy offered Wells a contract as an artist. The song Wells had sung, 'Bye Bye Baby', became her first single after some polishing and was released on the Tamla label. The song ended up a Top Ten R&B hit in 1960 and crossed over to pop radio where it peaked at number 45.
With Mary Wells' debut success, Gordy, who was at the time expanding Tamla Records into the Motown Record Corporation, immediately brought her back to the studio. Their work produced the follow-up hit, 'I Don't Want to Take a Chance', which equaled her first single's success. Her third single, 'Strange Love', met indifferent reception at radio and failed to chart. In 1962, Gordy decided to bring Wells and Motown's star songwriter Smokey Robinson together.
In early 1962, 'The One Who Really Loves You' swept across the nation. The ballad broke into the Top Ten at both R&B and pop radio, eventually peaking at number two in R&B and eight on Billboard's Pop chart. Gordy immediately followed with the release of 'You Beat Me to the Punch', a light-hearted tune that reached number one in R&B and replicated its predecessor's success in pop. The string of hits continued with 'Two Lovers', a tune that brought Wells her second R&B number one and her third pop Top Ten in a row. When the album The One Who Really Loves You was released, it broke the Top Ten in the album chart and became the best-selling Motown album to that point.
With a smash hit riding the airwaves of summer, Gordy decided to team the two stars of his label, Wells and Marvin Gaye, who had gradually built up momentum on the charts. Together, the result of their work became a hit album and featured two simultaneous top 20 hits, 'Once Upon a Time' and 'What's the Matter with You Baby'.
It was at this time that the Beatles openly called Wells their favourite American singer and invited her to tour with them throughout the United Kingdom. Wells accepted their invitation and was inspired to record Love Songs to the Beatles, an album featuring several songs penned by the British stars.
After a successful year, Wells reflected on her career and especially the financial reward (or lack thereof) she had received from her success. With encouragement from her husband, Herman Griffin and a lucrative contract with 20th Century Fox Records which promised a film career, Mary Wells sued Motown. She argued not only for larger royalties, but to dissolve the original contract she'd signed at age 17. Wells won the lawsuit and was rewarded a fair settlement. Gordy tried to prevent other labels from signing the successful singer to no avail, as she signed with Fox.
Wells immediately began recording new material for her new self-titled album. Despite her first three singles at the label being relative successes, the album brought in disappointing sales. The label began having second thoughts and pulled promotion for the album. They also failed to fulfill the film agreements, and the contract was dissolved in mid 1965 with Wells walking away with a small settlement.
Mary Wells was honoured by Stevie Wonder, Little Richard and others on an episode of the Joan Rivers Show in 1990. The following year, she testified for Congress to encourage government funding for cancer research. In the summer of 1992, Wells was hospitalised for pneumonia at the Kenneth Norris Jr Cancer Hospital in Los Angeles, CA.
Still suffering the effects of her cancer, her weakened immune system could not take the extra strain. Wells died on July 26, 1992 at age 49.