Born in Auckland, Gillian Ansell made her concerto debut as a violinist with the Auckland Philharmonia at the age of 16. At 19, an Associated Board Scholarship took her to the Royal College of Music in London for three years to study violin, viola and piano. She then won a German Academic Exchange (DAAD) scholarship for further study in Germany at the Musikhochschule Cologne with Igor Ozim and the Amadeus Quartet.
After working professionally in London, she returned to New Zealand to become a founding member of the New Zealand String Quartet in 1987. She was second violinist for two years before taking up the position of violist of the group. In 1992, Gillian founded the Adam Chamber Music Festival with a group of friends, performing five concerts in five days. Gillian has been the Artistic Director of the Festival since 2001.
In 2008 she was made a Member of the New Zealand Order of Merit (MNZM) for her outstanding services to music in New Zealand. In 2019 she served on the jury of the Banff International String Quartet Competition.
Gillian plays on a 1619 Nicolò Amati viola, generously loaned by the Adam Foundation. Gillian has performed at all 17 Adam Chamber Music Festivals.