The actor made his first appearance as laid-back student Scott Sabeka in September 2011.
Demba wrote on Twitter over the weekend: "Last day at oaks yesterday was cool gonna miss everyone apart from [Rob Edwards actor David Atkins] ... He's a pagon."
Channel 4 has since confirmed to Digital Spy that Demba filmed his final scenes on Friday, July 13.
Demba, also a boxer, told DS in April that he was glad writers had integrated a storyline involving his sporting passion.
Hollyoaks airs on weeknights at 6.30pm on Channel 4, with first-look episodes screened half an hour later at 7pm on E4.