Which chain's hamburger patties are square-shaped?

Wendy’s is the fast-food chain known for serving square-shaped hamburger patties.

The design dates to Wendy’s founding by Dave Thomas in Columbus, Ohio, in 1969. Thomas had grown up around Kewpee Hamburgers, a Kalamazoo chain that also used square patties, and adapted the idea for his own restaurant. Wendy’s presented the corners as a visual signal that customers were getting plenty of meat, with the patty extending beyond the circular bun.

The square shape is also practical. Wendy’s has said that square patties can fit efficiently on a grill, while the shape gives the burgers a recognizable appearance. The chain’s menu has included different patty sizes, such as Junior and Single patties, along with single, double, and triple configurations.

A common mix-up is confusing the patty shape with the bun: Wendy’s burgers generally use round buns, while the beef patties are square. Other chains and regional burger restaurants have used square patties too, but Wendy’s is the major chain most strongly associated with them.