The deal, which is performance based, begins from the start of next season and could earn the Foxes a seven-figure sum during the two-year term.
Foxes chief executive Tim Davies told the clubs official website: “It’s a perfect fit for this football club to have a company of the calibre and standing of Alliance & Leicester as its official sponsor.
“Both the football club and Alliance & Leicester have strong, well established roots within the Leicestershire community as well as a substantial national presence in their respective fields.
“During the next two years we are looking to develop a significant long-term relationship which will include a range of joint community initiatives involving the people of Leicestershire.”