What is the name of the signature square hamburger sold by Wendy's?

Wendy’s signature square hamburger is Dave’s Single.

Dave’s Single is named after Dave Thomas, who founded Wendy’s in Columbus, Ohio, in 1969. The hamburger uses a square beef patty, a shape associated with Wendy’s belief that its patties should appear to extend beyond the bun rather than being hidden inside it.

The Dave’s line includes single, double, and triple versions, with the number referring to the number of beef patties. The exact toppings and bun specifications may vary as menus are updated.

Dave’s Single should not be confused with the Baconator, which is a separate Wendy’s hamburger built around bacon and multiple beef patties. Wendy’s square-patty design is one of the chain’s most recognizable visual features and distinguishes it from the round patties common at many rival restaurants.