Harrison has been covering the role on an interim basis since Kevin Brennan left the company in July to join Premier Foods.
He will take responsibility for Kellogg’s £80m advertising budget for brands including Special K, Kellogg’s Corn Flakes and All-Bran.
He will report to UK managing director Greg Peterson.
Before taking over as marketing director Harrison managed marketing campaigns for Kellogg’s Crunchy Nut and Frosties brands.
Separately, Kellogg has promoted John Bryant, its US-based chief operating officer to chief executive. Current CEO David Mackay plans to retire in January.