A few notable establishments with a long history in the city:
Cherry Hill House: Built in 1822, the Cherry Hill House located at the intersection of Dundas St East and Cawthra is known to be one of the oldest houses in Mississauga[1]. It has been home to multiple restaurants over the years, but specific information about the current or previous restaurants is not mentioned.
Culinaria Restaurant: Culinaria is an elegant casual fine dining venue located in Mississauga. It is situated inside the old Elliott House, which was built in the 1860s by Scottish settler Adam Elliott[2]. While Culinaria Restaurant may not be the oldest in the city, the historical significance of the building adds to its appeal.
C & Dubbs Hamburgers: Mouthwatering Banquet Burger or the Sumo Burger. What of the oldest burgers shops in Mississauga.
Zets: The original Zet’s was founded in 1967
La Castile: La Castile opened in 1968 and I would be very surprised if the staff weren't exactly the same as back then.