[1][2][3] Donnelly is a founding member of the improvisational comedy group "Chuckle Duster", which performs occasionally in east London.
Donnelly's first acting was as Jason Winkler in Nickelodeon's TV series House of Anubis.
[4] He then guest starred in shows such as Doctors, Threesome, Misfits, Dancing on the Edge.
[6] In 2014, he played the role of a cocky footballer Olly Hunter in the wholly improvised spoof documentary United We Fall.
[8] In 2017, Donnelly played lead role of Prince Adrian in the Hallmark original movie A Royal Winter alongside Merritt Patterson.