Wendell's Burgers is a fast food restaurant seen in the Season Eight episode "Goobacks". The restaurant serves hamburgers and french fries. The name is a play on the real life burger franchise, Wendy's, using the male name Wendell.
The town of South Park is overrun by immigrants from the future, called Goobacks. The new arrivals work cheap and end up taking most of the jobs from the present day townsfolk. When the boys try to go to Wendell's they are dismayed that it is staffed by immigrants who don't speak English.
The building has a blue roof with yellow trim. This is the same template used for the similar M Burgers establishment.