The fire broke out at the fast-food restaurant on Bloxwich Road, between Green Lane and Blakenall Lane on March 9.
Video footage shared on social media showed flames taking over at the popular restaurant in Bloxwich as black smoke poured into the sky.
Three fire engines were required to put out the blaze and had to deal with the added complication of a carbon dioxide cylinder which was being stored in the outbuilding.
To celebrate its reopening, the restaurant will giving away four free chicken or vegan nuggets per transaction to locals.
The deal is first-come-first-served, and available exclusively to any customer who visits the Walsall restaurant on Tuesday, March 29, only.
Nobody was hurt during the incident, but the restaurant did have to be closed for more than two weeks to allow for refurbishment.
Salim Janmohamed, managing director at Karali Ltd, who run Burger King, said: "We are thrilled to be reopening the Burger King branch in Walsall and welcoming customers again.
"We know they love the great-tasting food of Burger King, so we are very excited to bring back all their favourites."