- Role: Trainer
- Dimentions: Wingspan 10.97m, Length 8.81m, Height 3.18m
- Engine: 1 x Armstrong Siddeley Lynx IV (160 hp or 180 hp) or Lynx IVC (215 hp)
- Crew: 2
- Number in service: 6+
- Country of production: Great Britain
- Years in service: 1925 – 1941
The Avro 504 served as the basic training airplane of the Naval Flying Corps. The first 6 were ordered in 1925, while a small number of Avro 504 was built at the Faliro Airplane Factory in 1934-35.
The hydroplane variation was the Avro 504O and it was quite different, as a vertical stabilizer was added. Both types served in the unified Air Force until W.W. II