[2] Porteous made his acting debut during an episode of the BBC medical drama Holby City as Rufus Lucas on 15 September 2015.
[3] He then featured in a 13 episode stint of the BBC soap opera EastEnders as Mark Fowler between 11 August and 9 September 2016.
Despite Mark having been born and brought up in the United States, Porteous did not use an American accent for the role.
[4] On 13 September 2017, he first appeared in the ITV soap opera Emmerdale as young businessman Tom Waterhouse, a name that turned out to be an alias, the character's real name being Joseph Tate.
Porteous played Lord Wetherby, Henry Granville's (Julian Ovenden) lover, in the first season of the 2020 Netflix period drama Bridgerton.