Judith Veronica Mowatt was born in Gordon Town, St. Andrew Parish, Jamaica in 1952.

At the age of 13, she became a member of a dance troupe that toured Jamaica and other islands in the Caribbean. 

Mowatt initially attracted attention as the lead singer of a vocal trio, the Gaylettes, also known as the Gaytones, that she formed with Beryl Lawrence and Merle Clemonson in 1967. The Gaylettes harmonized on a rich mix of R&B and Jamaican dance music. 

Mowatt's greatest break came when vocalist Marcia Griffiths asked her to sing harmony on a track that she was recording at Studio One with her duo partner Bob Andy in 1974.

Rita Marley, the wife of Bob Marley and the mother of Ziggy Marley, was also hired to sing on the tune. The three women hit it off so well that Griffiths invited Mowatt and Marley to sing the Supremes tune "Remember Me"  that night at the House of Chen in New Kingston. The appearance was so successful that they agreed to continue performing together. From that day, the I-Threes were born.

Around the same time, Bob Marley was beginning to rebound from his split with Peter Tosh and Bunny "Wailer" Livingston. During a visit to the home of reggae producer Lee Perry in Cardiff Crescent in the Washington Gardens section of Jamaica, it was suggested that Marley incorporate the I-Threes into his performances. The I-Threes continued to thrive with Bob Marley until his passing in May 1981.

Five years later, Mowatt and the I-Threes were touring in a package show that featured musicians from The Wailers and introduced Ziggy Marley & the Melody Makers to North American audiences.

In addition to her work with Marley and the I-Threes, Mowatt continued to pursue a solo career. Her debut album Mellow Mood was the first to be recorded at Marley's Tuff Gong Studios. Mowatt went on to record her second album at Coxsone's Studio One entitle  Black Woman, which became the first reggae album recorded by a woman acting as her own producer.

She went on to record ten more solo projects and was nominated for a Grammy in 1985 for her album Working Wonders.

The legacy of Judy Mowatt will forever be remembered as a stellar vocalist and one-third of the most influential female vocal groups in reggae's history.