The ad, created by Fallon, features dancing clothes in an initially lifeless charity shop.
Individual clothes fall from the rails, rise from the floor and burst from cupboards, and the charity shop is transformed into a dancing extravaganza.
The ad is set to the 1980s soundtrack of Jermaine Stewart’s ‘We don’t have to take our clothes off'.
"Charity Shop" airs tonight and continues the Glass and a Half Full Productions series that started with "Gorilla".
Fallon's executive creative director Augusto Sola and creative Sam Hibbard worked on the project. "Charity Shop" was produced by Riff Raff Films and directed by Megaforce. Post-production was by MPC, with video effects by Michael Gregory.
Cadbury has put £6.2m into the campaign, which will run across digital, events and PR, with media handled by PHD.
Julie Reynolds, marketing manager for Cadbury Dairy Milk, said: "For us Cadbury Dairy Milk is about creating moments of joy that make people smile. We believe this production is another great way of doing just that."