The João Belo class, also known as Comandante João Belo class, is a class of four frigates of French design, based on the Commandant Rivière class but fitted for tropical service. Ordered by the Portuguese Navy in 1964, the four ships of this class were constructed at the shipyard in Nantes, France between 1965 and 1967. The first ship entered Portuguese service in 1967. The frigates were used for ocean patrol of Portuguese colonies and later, joined NATO's STANAVFORLANT unit. The first unit was discarded in 2003, followed by a second in 2004. The final two ships were taken out of service in 2008 sold to the Uruguayan Navy. The third ship was discarded in 2021, and the last ship was decommissioned on 12 August 2022.

The Commandant Rivière class was a class of frigates built for the French Navy in the late 1950s and early 1960s. Labeled "aviso-escorteur", they were designed to perform the role of overseas patrol in peacetime and anti-submarine escort in wartime. This vessel class is named after the French Navy officer Henri Rivière (1827–1883).