A fluid filter (1) comprises a housing (3) provided with a fluid inlet (11) and a fluid outlet (19), filter means (45) being mounted in the house (3) between the fluid inlet (11) and the fluid outlet (19) to filter fluid flowing through the housing (3). Actuation means (43) is provided to move the filter means (45), in use, within the housing (3) to dislodge particles of filtered material from the filter means (45) so as to clean the filter means (45). A filter assembly comprising a plurality of such filters is also provided.