Jeff Heaney is a recurring supporting character in the television series Peep Show, and is portrayed by Neil Fitzmaurice.
Jeff is a colleague and nemesis of Mark's at JLB Credit. The two frequently clash over the affections of Sophie, with Jeff's manly, intimidating behaviour serving as a foil to Mark's mild-mannered persona.
He is a work colleague of Mark's at JLB Credit and an intimidating, manly bully from Merseyside. The two repeatedly clash, not least for the attentions of Sophie. He lives at 33 Ringfield Road.
In the later series, as Mark and Sophie's relationship takes its course, he is frequently seen mocking Mark. After their relationship falls apart, Jeff appears to gradually get close to Sophie again. Mark's anger over this peaks when Sophie even considers naming their child 'Geoff'. However, Sophie sees no connection between this name and that of Mark's rival, instead claiming that she takes it from a relative. In series 7 he becomes the baby's godfather when Mark and Jeremy both fail to turn up on time, and it appears that Jeff and Sophie are back in a relationship by the end of the series, which is a major torment to Mark, who constantly believes that his son will think Jeff is his father. Jeff confirms they are back together when he comes to Mark's house to collect the baby in Series 8. By series 9, though, Sophie is with someone else. However, Jeff eventually replaces Mark at the bank in the series finale. David Mitchell once joked that if the show came back Mark would most likely get his comeuppance and finally punch Jeff in the face.