[1] On stage, Gaumond is best known for playing the leading roles of Galileo in the Queen musical We Will Rock You, Emmett in the original London production of Legally Blonde and Miss Trunchbull in the RSC's Matilda.

2002 saw Gaumond make his professional West End debut at the Prince Of Wales Theatre where he understudied the roles of Malcolm, Jerry and Ethan in The Full Monty.

In 2009, Gaumond was cast to play the male lead (Emmett) in the original UK production of Legally Blonde alongside Sheridan Smith as Elle Woods at the Savoy Theatre in London in January 2010.

In the summer of 2012, Gaumond made a small appearance on TV during Andrew Lloyd Webber's auditions for the role of 'Jesus' in his upcoming UK arena tour of the show Jesus Christ Superstar.

[8] In early 2013 it was announced that Gaumond would return to the West End starring as Alberto Beddini in Top Hat at the Aldwych Theatre, alongside Broadway actors Gavin Lee and Kristen Beth Williams.

[11] In June 2013, it was announced that Gaumond would be joining the cast of the Royal Shakespeare Company's multi-award winning production of Matilda at the Cambridge Theatre, playing the iconic role of headmistress Miss Trunchbull.

[16] This specially adapted version of the show, developed in close collaboration with The National Autistic Society, was designed for people with autism and learning disabilities.

Gaumond appeared in Dirty Rotten Scoundrels at the Savoy Theatre from 11 November 2014, replacing Rufus Hound in the role of Freddy Benson, the conman portrayed by Steve Martin in the original movie version.

Next, Gaumond played the role of Beadle Bamford in English National Opera's production of Sweeney Todd at the London Coliseum, opposite Bryn Terfel and Emma Thompson, from 30 March to 12 April 2015.

[18] In April 2015, it was announced that Gaumond would star as Adam Pontipee in Seven Brides for Seven Brothers at Regent's Park Open Air Theatre, from 16 July to 29 August 2015.

[21] Gaumond was cast as the Baker in a new production of the Tony Award-winning Broadway musical Into the Woods at the Royal Exchange Theatre, Manchester, from 4 December 2015 to 16 January 2016, directed by Matthew Xia.

Directed by Joe Harmston, the new play starred Hollywood icon, Academy Award nominee and Golden Globe winner, Anne Archer (Fatal Attraction; Patriot Games; Clear and Present Danger) as Jane Fonda.

The London Musical Theatre Orchestra, formed of 32 musicians, performed the fully orchestrated score with a chorus and West End cast, starring Robert Lindsay as Scrooge.

Playing at The Old Vic from 20 November 2017 to 20 January 2018, the world premiere production was directed by Matthew Warchus and starred Rhys Ifans as Ebenezer Scrooge.

[29] On 12 July 2018, it was announced that Gaumond had been cast in Marianne Elliott's highly anticipated new production of George Furth and Stephen Sondheim's Company, which played at the Gielgud Theatre from 26 September 2018.

[37] Alongside Gaumond, the production also starred Joe Thomas, Laura Patch, Summer Strallen and Bo Poraj (who replaced the previously announced James Lance before rehearsals started).

After the pandemic and several television appearances, 2023 marked Gaumond's return to the stage, playing Keir Hardie in the world premiere of Sylvia at The Old Vic, from 27 January to 8 April 2023.

[41] Gaumond headlined his first solo show on 22 May 2011 at the Leicester Square Theatre, where he performed a mix of covers and original material, as well as some duets with special guests including Ramin Karimloo.