The company are based close to the League One club's Gresty Road ground and have sponsored Crewe's shirts for the past four seasons.
"Everyone is delighted that Mornflake Oats have agreed to extend their sponsorship of our shirts. We have enjoyed working closely with such a community based company," Crewe chairman John Bowler told the club's official website.
"We are proud to have the new Mornflake logo appearing on our shirts over the coming seasons.
"Like ourselves, it is a company that focuses on promoting healthy lifestyles to the local community."