She was born in Melbourne, Australia. Performing since the age of 12, Amorosi was discovered and signed to a recording contract in 1997. After being signed to MarJac Productions (co-owned by managers Mark Holden and Jack Strom), recording a promo CD and gaining a deal with Transistor Music Australia, her first single, titled "Have A Look", was a hit in Australia and narrowly missed reaching the Top 10 when it was released in 1999. Amorosi received critical praise from the Australian media for the power of her voice and the maturity of her lyrics.

A second single, titled "Absolutely Everybody", was an anthemic dance track that reached the Top 10, and with its positive lyrics, became an unofficial theme song for various cultural events. It remained in the Australian Top 20 Singles Chart for over six months after it's release.

In 2000 two more singles "Shine" and "The Power" became major Australian hits, and her album The Power reached number one on the Australian album charts. Amorosi then performed at the NRL Grand Final. Her largest audience came in September 2000 with performances at the Opening and Closing Ceremonies of the Sydney 2000 Summer Olympics and at the Paralympic Games. At the Opening Ceremony of the 2000 Summer Olympics she sang the Olympic song titled "Heroes". In 2001 she performed at the Australian Football League grand final.

"Absolutely Everybody" was released internationally and reached the Top 10 in the United Kingdom, and throughout Europe and South East Asia shortly after her Olympics performances, but subsequent releases met with little success. For her service to music she was later awarded the Australian Centenary Medal by the Government of Australia.

She continues to maintain a low-profile presence in the music industry, recording and performing in Australia and throughout the world.

Formerly being critical towards commercials in television and radio, Amorosi recently contracted to a 5-year-term TV advertisement campaign for Australia's leading independent vehicle heater systems "Australheat".

On 25 January 2006, it was revealed on the AccessAllAreas.net website that Vanessa is now under the management of Ralph Carr, having completed her seven year management with MarJac Productions. She is quoted on the website as saying, "I have been with my previous management for seven years and thought both parties had gone as far as we could together... Moving over to Ralph Carr Management seemed like a natural progression, given the acts he has successfully managed. I am excited and enthused." It is reported that Amorosi's new album will be released later on in 2006, but not before her "Best Of..." CD is released.