Joss (30), who hails from Uffculme and still lives in Mid Devon, as well as attending to support the event, says she will take to the main stage to sing a song or two at the biggest free celebration of the lesbian, gay, bisexual and transgender (LGBT+) communities in the county of Devon.
Joss recently returned from her Total World Tour which has seen her perform gigs at large and small venues across many continents.
Joss rose to fame in 2003 with her multi-platinum album "The Soul Sessions", which made the 2004 Mercury Prize shortlist.
Her second album, the similarly multi-platinum "Mind, Body and Soul", topped the UK Albums Chart for one week and spawned the top 10 hit "You Had Me".
Both the album and single received a nomination at the 2005 Grammy Awards while Joss was nominated for Best New Artist, and in the annual BBC poll of music critics."Sound of 2004" was ranked fifth as a predicted breakthrough act of 2004.
She became the youngest British female singer to top the UK Albums Chart.
Joss's third album "Introducing Joss Stone", released in 2007, became her first top five album in the United States. Her fourth album "Colour Me Free!" and her fifth album "LP1" both reached the top 10 on Billboard.
Throughout her career, Joss has sold 14 million albums worldwide, establishing herself as one of the best-selling artists of her time, best-selling soul artists of the 2000s and best-selling British artists of her time.
Her first three albums have sold more than 2,722,000 copies in the US, while her first two albums have sold more than 2,000,000 copies in the UK.
Stone has earned numerous accolades, including two Brit Awards and has appeared in film and television roles.
In 2012 she was said to be the fifth richest British musician under 30.
"The Soul Sessions Vol 2", released in 2012, was her fourth consecutive album to reach the top 10 Billboard 200.