Elway, who retired in 1999, is currently executive vice president of football operations for the Denver Broncos and part owner of four Elway's Restaurants and automobile dealerships bearing his name.
Neptune chief financial officer André Godin said: "In his amazing 16 year career, which included two Super Bowl Championships, a Super Bowl MVP, an NFL MVP award, and nine NFL Pro Bowls, John Elway is easily one of the most recognizable and successful athletes of all time."
Chief executive Henri Harland added: ''This is an exceptional day for our company and we could not be more pleased to partner with one of the best professional football players to ever play the game.”
Neptune, which is tripling production capacity at its Sherbrooke plant in Canada, recently announced that construction of a new factory that will manufacture its krill oil products in Asia, will begin late this year or early next.