In the ad, Jackson, 22, appears as an angel holding her rescued cat Alfie next to the words "Be an Angel for Animals: Adopt. Don't Buy!" The ad was shot by ace photographer Nikki Lyons.
"Every time someone buys a cat or a dog from a breeder or a pet shop, a cat on the streets or in an animal shelter loses his or her chance at finding a good home", Jackson said.
"We can stop the cycle of animal homelessness and save lives by opening our hearts and homes to a loving cat or dog from an animal shelter instead of buying animals from breeders or pet shops," she added.
Jackson found Alfie when he was just 6-week-old, abandoned on the side of a busy road in a box with four other kittens. Three of them didn't survive, and Jackson and her sister adopted the other two, Alfie and Frankie.
Jackson has been a long-time animal rights supporter and often speaks out on social-networking forums about issues such as animal adoptions and rescues and cruel horse-drawn carriages.
She was crowned Miss Teen World in 2009 and Miss Liverpool in 2010. She also made her debut in Telugu cinema with 'Yevadu' and will soon be seen in a Tamil film opposite Chiyaan Vikram.