Harrison joined Asda five years ago through the retailer's graduate scheme where he was a project manager, reporting directly to Asda boss Andy Bond. He will now lead a three-strong buying team, building strategic relationships with suppliers.
"A new role always brings challenges, but I'd say the biggest will be having the chief executive checking my numbers every morning!" he said.
Harrison replaces Stuart Menzies, who is taking up a wider role within Asda's impulse grocery team.