Harris will be responsible for on and off-air marketing as well as consumer PR and heading up the channel's creative teams.
Specifally, Harris will have a remit to broaden the channel's appeal and better compete against other commercial rivals, such as ITV, and the BBC.
Channel 5 will also want Harris to make better use of the Richard Desmond-owned group's portfolio of media assets, which includes the Daily Express and Sunday Express and the Daily Star newspaper, along with celebrity magazines such as OK! and Star.
A particular focus will be the cross-promotion of the channel across its various assets.
Channel 5 currently does not have a marketing director and so Harris will fill the top marketing role at the broadcaster.
She will report directly to Stan Myerson, group joint managing director of Nothern & Shell group, which owns Channel 5. She will start on 21 March.
Harris has been marketing director for MTV since 2009. She has also held the role of marketing director at the weekly division of Natmags, where she helped launched Real People magazine.
Stan Myerson said: "I’m delighted Zoe is set to join us at Channel 5.
"With her top-flight marketing background, having worked on some of the UK’s biggest brands, her creativity and her energy, Zoe will be a huge asset to the broadcaster as we look to broaden our appeal and make full use of the cross media opportunities available in the Northern & Shell portfolio."
The show was presented by Matt Johnson and Kate Walsh, after the original host, Denise Van Outen, dropped out of her contract three days before the debut show, after what is rumoured to be a spat with Desmond.