The mum-of-two says she is "excited" to have been chosen for the role and is looking forward to giving deserving women the "recognition they deserve".
Coleen said: "It is an honour to be chosen to act as an ambassador for such a brilliant campaign.
"There are so many truly inspirational mums out there who do an amazing job and I am excited to be involved with the Awards to give them the recognition they deserve."
In May, Coleen gave birth to her and husband Wayne's second son Klay Anthony. The couple are also parents to three-year-old Kai.
Coleen and those behind the Awards are encouraging the public to nominate the most deserving mums in the UK. Those shortlisted will be celebrated at a star-studded luncheon at a luxury London hotel just before Mother's Day next year.
Debbie Chernin, from Tesco, said: "Coleen was chosen to be our ambassador because charity work lies very close to her heart.
"She manages to juggle a busy home life with two young boys with her business life as a fashion designer, as well as several TV projects and columns she has been involved with.
"Plus she does extraordinary work for several charities, including Claire House Children's Hospice, Alder Hey Children's Hospital and she has also been involved with the Jeans for Genes charity. She is a popular personality and always cheerful."
To nominate a mum for the Awards, click here!