Robyns grew up in Liverpool, England. Moving to Bristol at the age of 10 he became involved with several local theatre and youth music groups. Performing in such varied shows as Purcell's Dido and Aeneas and Handel's Messiah to Kander and Ebb's classic musical Cabaret. He worked on new material with Playbox Theatre Company performing NEWS and performed two new operas with MusicBox Youth Opera; Fox at the manger and Brundibar. In 1999 Robyns moved to Cardiff becoming involved with Welsh National Youth Opera. With WNYO he performed The Beggar's Opera, The Elixir of Love and Dido and Aeneas. Robyns was also part of Black MountainMale Voice Choir – the official Choir of the 1999 Rugby World Cup, singing at Wales games and the opening and closing ceremonies at Cardiffs Millennium Stadium. With his friends, Robyns ran a weekly drama group and worked on a production of Berkovs West whilst studying Music, Theatre Studies and Sociology A Level. During this time Robyns was part of the National Youth Choir of Great Britain singing in venues around the country including Walton's Belshazars Feast at the Millennium Proms at the Royal Albert Hall.
Graduating in 2004 Robyns joined the UK touring company of Miss Saigon understudying the role Chris and playing the part on many occasions. After this he played the role of Mark Cohen in Rent with the English Theatre Frankfurt, Germany. In June 2006 Robyns played the roles of Princeton and Rod in the original London cast of Avenue Q the musical in London's West End. He left the show in December 2007. Robyns was part of the company for the concert version of Chess at the Royal Albert Hall on 12 and 13 May 2008. Robyns played the role of Marius in Les Misérables at the Queen's Theatre until leaving the show on 23 June 2009. He has rejoined the cast of Les Misérables during the 25th Anniversary International Tour of Les Misérables 2010 as Enjolras and is on the live recording Album. Robyns appeared at the O2 Arena on 3 October alongside current/previous cast members from across the world in a 25th Anniversary concert. In 2008 Robyns recorded a song for the CD Act One – Songs From The Musicals Of Alexander S. Bermange, an album of 20 brand new recordings by 26 West End stars, released in November 2008 on Dress Circle Records, and recorded the role of robot ThreeSix in a concept album of Laurence Mark Wythe's musical The Lost Christmas. He has previously recorded material for Whyte and in 2005 appeared in a showcase of one of the composer's musicals at Greenwich Theatre. In 2011 Robyns joined the cast of Spamalot as part of the UK Tour, performing the role of Sir Galahad. The show toured the UK throughout 2012, before a return to the West End at the Harold Pinter Theatre. In 2014 Robyns joined the original London cast of Memphis, playing the role of first cover Huey. In 2015, starred as Caractacus Potts in the UK tour of Chitty Chitty Bang Bang In 2016 Robyns played Emmett Forrest in the Leicester Curve production of Legally Blonde, and performed in both the UK tour of Sister Act as Eddie and The Wedding Singer as Robbie Hart. In 2018 Robyns joined the West End cast of Hamilton at the Victoria Palace theatre playing King George. In December 2019, Robyns will take over the role of Jean Valjean in the new production of Les Misérables in London's West End.
