He replaces Matthew Cook, who has left the company.
Allaker will be succeeded as Nike vice president and general manager of the UK and Ireland by Marc Van Pappelendam, who was most recently VP/GM of Nike eastern and central Europe, based in the Netherlands.
Throughout his 21-years at Nike, Allaker has held various positions in finance and operations at Nike world headquarters in Beaverton, Oregon and at the Nike European headquarters.
He has been VP/GM of the UK and Ireland business since 2006 and his role prior to that was VP of finance, planning and operations for Europe, Middle East and Africa.
Nike saw profits fall 21% last year after it was hit by restructuring costs and the global economic downturn.
The sportswear manufacturer reported net income fell to $1.5bn (£920m) in the year to 31 May despite seeing a 3% year-on-year uplift in revenues to $19.2bn (£11.8bn).