The 40-year-old had been without a club since leaving his post as St Helens head coach in April, but he has not had to wait long to get back into the game, as he will now assist Leigh boss Neil Jukes for the remainder of the campaign as the Centurions bid to preserve their Super League status.
Cunningham will replace Leigh owner Derek Beaumont in the role and he insists he has not joined the club to tread on anyone's toes, as he merely wants to use his knowledge and experience to help the club end the season strongly.
Cunningham said: "I have not come in to take anyone's place, but to add my knowledge and experience as this stage of the season."
Leigh are currently third in The Qualifiers, with only the top three teams guaranteed their place in the top-flight for next season.
The Centurions were beaten 20-16 by Hull KR on Saturday, but they will be hoping to return to winning ways when they take on Catalans Dragons at the Stade Gilbert Brutus next weekend.