Mother's appointment comes as Unilever plans to reinvent the fast-food brand, giving it a healthier positioning and making it more attractive to new consumers, particularly women.
Changes will include improvements to ingredients, the removal of additives and new packaging.
Unilever ditched United's "slag of all snacks" strategy last year in favour of the "have you got the Pot Noodle horn?" campaign.
Stef Calcraft, a partner at Mother, said: "Mother has noodles in her blood. The pot makes them extra special."