Roberts-Smith was born in Perth, Western Australia, to Sue and Len Roberts-Smith. He attended Hale School, as did his older brother, Ben Roberts-Smith. He graduated from the Western Australian Academy of Performing Arts in 2008 where he sang in an alternating cast the role of John Proctor in the Australian premiere of Robert Ward's opera The Crucible. He joined Opera Australia in 2009 where he made his principal debut as Moralès in Carmen in 2011. That same year Roberts-Smith joined the Opera Australia Young Artist Program and subsequently the principal artist ensemble. Performed Opera Australia repertoire includes Macbeth, The Mikado, A Midsummer Nights Dream, La bohème, Lakmé, Eugene Onegin, Tosca, Manon, La traviata, Carmen, Der Rosenkavalier, La sonnambula, Les pêcheurs de perles, Madama Butterfly, La fanciulla del West, Il trovatore, The Magic Flute, Bliss, Rigoletto, and Don Giovanni. He has won numerous Australian and international awards, including the Joan Sutherland Vocal Scholarship, first place in the 2009 Australian Singing Competition, Symphony Australia Young Vocalist Award, Best Performance Award at the 2014 Paris Opera Awards, and the inaugural Deutsche Oper Berlin Award in 2016. He joined The Ten Tenors from 2015 to 2017, and toured Australia, the US and Argentina with them. Recorded DVD performances include Remendado in Carmen for Opera Australia in their 2013 Handa Opera on Sydney Harbour by ABC Classics, and Der Rosenkavalier recorded live at the Sydney Opera House. The West Australian Opera selected Roberts-Smith as a Mentored Artist in 2015. He was invited to sing the national anthem that year at a commemoration in Melbourne of the victims of shooting down of Malaysia Airlines Flight 17. He then toured China in 2015 with the Australian International Opera Company as Count Almaviva in Mozart's The Marriage of Figaro. On the concert stage, he sang with the Queensland Symphony Orchestra in Messiah that year. Roberts-Smith appeared opposite Emma Matthews in 2016 as Zurga in the West Australian Opera production of Bizet's Les pêcheurs de perles. For Deutsche Oper Berlin he has appeared in over a dozen productions, including La traviata opposite Leo Nucci in August 2017, Il Barbiere di Siviglia in October 2017, Lady Macbeth of Mtsensk in April 2018, Rigoletto in May 2018 opposite Simon Keenlyside, Il viaggio a Reims in June 2018, and Andrea Chénier in November 2018. In 2019, Roberts-Smith appeared in La traviata for West Australian Opera, understudied the role of Judge Turpin and performed in the TEG Life Like Company's starring Anthony Warlow and Gina Riley, performed Brahms' Requiem with the Sydney Philharmonia Choirs, the title role in Le Nozze di Figaro for the Australian International Productions tour of China, starred in Barry Conyngham's Australian opera Fly, and completed a Graduate Diploma of Human Resource Management from Edith Cowan University. In July 2019, Roberts-Smith was invited to join the Golden Key International Honour Society in recognition of his academic achievements. In October that year, Roberts-Smith performed the title character in the Australian premier of The Enchanted Pig in collaboration with internationally renowned Director Gale Edwards AM and Academy Award winning costume designer Tim Chappel. Performances took place in the Yarra Valley in regional Victoria as part of Australia's only International opera festival
