The Grigorovich M-24 was a Soviet biplane flying-boat built during the 1920s.
Dmitri Grigorovich began developing the aircraft in April 1922, whilst testing the successful Grigorovich M-9. Flight tests with the new aircraft, which featured a 14-metre wingspan and a maximum speed of 160 km/h, began in 1923 and subsequently 40 of the type were produced and were delivered from April 1924. The flight performance was poor, however, with pilots and maintenance personnel complained of many defects.
Following these complaints, Grigorovich began working on a revised version of the aircraft, the M-24bis. One improvement made was building a stronger engine of 260-hp, as opposed to the original (220-hp). Twenty M-24bis examples were built, being flown until 1926 by the Soviet Navy as coastal reconnaissance aircraft.