He originated leading roles in multiple West End productions, including Drew Boley in Rock of Ages and William Shakespeare in & Juliet.

[1] He is a graduate of Arts Educational School, where he played the lead role of "Tony" in West Side Story.

[1] Tompsett made his professional and West End debut in 2002 in the Madness/Tim Firth musical Our House,[2] directed by Matthew Warchus, at London's Cambridge Theatre.

[2] Immediately prior to joining the original cast of Wicked, in 2006, he appeared in Trevor Nunn's production of Peter Shaffer's The Royal Hunt of the Sun, at the National Theatre.

He is a member of the original London cast, having previously performed in the ensemble and serving as the understudy for Fiyero, before replacing Adam Garcia in 2007.

[6] From November 2014 to 24 January 2015, Tompsett played the role of Phil Davis in the musical White Christmas alongside Darren Day in Leeds.

[7] From 16 March to 14 August 2016, Tompsett played the role of Sky Masterson in the West End revival of Guys and Dolls following its transfer to the Phoenix Theatre in London.

[8] Tompsett reprised the role for the show's Israeli premiere at the Opera House in Tel Aviv for 10 performances.

In late 2008 he released his debut album entitled "Sentimental Heart", with all of the songs written, performed and produced by Tompsett.