[citation needed] Two weeks after graduating, O'Byrne was recruited to the Australasian tour of Andrew Lloyd Webber's The Phantom of the Opera, covering the role of Christine Daaé.
O'Byrne was chosen by Andrew Lloyd Webber to create the role of Christine Daaé[4][5] in the new Australian production of Love Never Dies, his sequel to The Phantom of the Opera.
[11][12] Following Love Never Dies, O'Byrne made her West End debut on 3 September 2012 as Christine Daaé in The Phantom of the Opera opposite Marcus Lovett in the flagship production of the show at Her Majesty's Theatre, London.
[13][14][15] In 2013, she played Anne Egerman in Alex Parker's production of A Little Night Music with Janie Dee and Joanna Riding at the Yvonne Arnaud Theatre at Guildford.
She was invited to sing Andrew Lloyd Webber's Pie Jesu at Westminster Abbey at the Memorial Service for Sir David Frost[21] on 13 March 2014.
[23][24] In January 2015, she reprised the role of Anne Egerman in Alex Parker's production of A Little Night Music with Janie Dee and Joanna Riding at the Palace Theatre as part of the show's 40th anniversary celebrations.
[26] Returning to her hometown Melbourne, Australia in July 2015, she performed the role of Maria in a sell-out season of West Side Story at the State Theatre for The Production Company.
[citation needed] Later that year in Sydney, she appeared with David Campbell in the Hayes Theatre's An Evening With… cabaret, alongside Judi Connelli, John Diedrich, Amy Lehpamer, James Millar and Alex Rathgeber.
[31] She joined the UK tour of Guys and Dolls playing Sarah Brown opposite Louise Dearman and Richard Fleeshman from March to July 2016.
[citation needed] Anna continued with My Fair Lady to Queensland Performing Arts Centre in Brisbane in March, with Charles Edwards as Henry Higgins, and at the Regent Theatre in Melbourne from 16 May to July 2017.
[42] She returned to the London stage from November 2017 to February 2018 as Laura Fairlie in Andrew Lloyd Webber's The Woman in White at the Charing Cross Theatre.