Fernando José Mendes Rosas ComL (born 18 April 1946, in Lisbon) is a Portuguese historian, professor and politician, being one of the founders of the Left Bloc.

The events of May 1968, and the Soviet invasion of Czechoslovakia, in August of the same year, led him to opt for the abandonment of the Communist Party.

He participated in Portugal's first public protest against the Vietnam War, supported by sectors that were linked to the Students' Democratic Left-Wing, organization which he helped found in late 1968.

Rosas took part in the foundation of the maoist Re-Organized Movement of the Party of the Proletariat (MRPP) in 1970, along with figures such as Arnaldo Matos.

In 1999, with Francisco Louçã from the PSR, Luís Fazenda from the UDP and Miguel Portas from Politics XXI, Rosas became one of the founders of the Left Bloc (BE), becoming the leader of its Permanent Commission.

Following the same year's legislative election, in which the Left Bloc entered Parliament by winning 2 seats, Rosas became a Member of the Assembly of the Republic from Lisbon.

Rosas served as the president of the Institute of Contemporary History (IHC) between 1994 and 2013, historical consultant for the Mário Soares Foundation and the director of História magazine between 1994 and 2007.

[9] Rosas is a member of the Executive Commission of the Resistance and Freedom National Museum at the Peniche Fortress, where he was arrested during the Estado Novo regime.