Peasant uprisings, strikes, student movements, red banners, global Maoists, resistance fighters, fiery speeches, guerilla bands, communists, slave rebellions, and a visit to Marx's grave at Highgate. Your one stop shop for left politics, broadly conceived, depicted on film.
(Note: this list zooms in on fictional or documentary depictions of conscious political action, rather than all films about social realism, injustice, class conflict (or allegories about these things), talking head and archival footage docs, or films using left aesthetics – which would be a far broader category!)