Parker starred in the TVNZ soap opera Shortland Street as Guy Warner, a character that has made several return appearances, most recently involving a story where Guy ran off with his brother's wife, Toni, only to return months later as a drug addled loser who attempted to use his daughter to score drugs for him.

[1] Parker appeared as Haldir of Lórien in The Lord of the Rings film trilogy from 2001 to 2003, and as Sabas in Underworld: Rise of the Lycans (2009).

Parker starred as Darken Rahl in Sam Raimi and Rob Tapert's syndicated television series Legend of the Seeker.

From 2014 to 2017, Parker played Lord Stéphane Narcisse in the CW period romance drama series Reign.

portraying the Kree Taryan in 2018, and later had a recurring role during the first season of the 2018 reboot of Charmed playing Alastair Caine.