The agency won the business after a pitch and will work with the charity on activity that is set to include outdoor, print, digital and mobile advertising.
Shelter has previously worked with media agencies on an ad hoc basis and its recent campaigns include a poster campaign that broke last month to encourage those facing homelessness to seek advice. The charity used the strapline: "We can help."
The creative agency Amplify, which worked on a pro bono basis, developed the campaign.
In March, the agency created an online five-minute film, featuring the comedian Sean Lock, for Shelter’s Facebook page. The film was produced by Irresistible Films.
In previous years, Leo Burnett has created award-winning campaigns for Shelter, including its "house of cards" activity that included a 60-second TV spot as well as original art created by the likes of Damien Hirst and Marc Quinn, which was auctioned to raise funds for the charity.