He began his career in the early 2000s, and spent three years working at an international business firm while auditioning and performing in amateur theater at night.

In 2004, Arcelus appeared in the movie musical Temptation, with Broadway stars Alice Ripley, Adam Pascal, and Zoe Saldaña, among many others.

Arcelus was featured on iChannel, an interactive 2006 web-series about "a self-conscious young man who finds his life taken over by a video blog.

"[7] He starred as Bob Gaudio in the Broadway production of Jersey Boys from January 10, 2008, to January 11, 2009. before starring in Happiness, a musical which ran Off-Broadway at Lincoln Center Theater's Mitzi E. Newhouse Theater for fourteen weeks beginning on February 27, 2009.

[9] He originated the role of Buddy in Elf the Musical for a limited engagement run from November 10, 2010, through January 2, 2011, at Broadway's Al Hirschfeld Theater.

[13] In November 2011, Arcelus starred in an off-Broadway limited engagement musical production of The Blue Flower at Second Stage, along with Marc Kudisch and Teal Wicks.

In 2013, Arcelus reprised his role of Jake Brigance in the Broadway production of A Time To Kill at the Golden Theatre in New York City, which premiered on October 20, 2013.

[17] Following four years of improvisational rehearsals, the musical debuted regionally in 2013 at the George Street Playhouse in New Jersey before receiving a pre-Broadway workshop in 2014.

He joined the cast of the Steve McQueen miniseries Codes of Conduct, which was given a limited series order by HBO in 2015.

In August 2022, it was announced that Arcelus would return to Broadway by replacing Brian d'Arcy James as the Baker in the revival of Into the Woods beginning September 6 and that he would star alongside his wife Stephanie J.

[24] In December 2022, it was announced that Arcelus and Block would reprise their roles in the production's U.S. national tour, which launched in early 2023.