Mattress Prince's mattress store is a mattress store in Gravity Falls.
In "Tourist Trapped," Mabel tries to get a young employee dressed as a prince to date her. She frightens the employee by popping out from behind the balloons and whispering "Take me with you!" after he announces the mattress sale.
The only section of the store seen contains a king sized bed with two mattresses on each side, a "Sale" sign connected to some multi-colored balloons, and a banner hanging on the wall that says "YE OLDE DEALS!!!", along with yellow walls and a red, orange and yellow tiled floor.