The Avro 558 was a British single-engined ultralight biplane built by Avro at Hamble Aerodrome.
The Avro 558 was designed for the 1923 light aircraft trials for single-seaters at Lympne Aerodrome. Two Avro 558 biplanes were built, they were biplanes powered by motorcycle engines (one with a B&H twin-cylinder air-cooled engine, the second with a 500 cc Douglas engine). The first aircraft was modified with a 698 cc (42.6 in<sup>3</sup>) Blackburne Tomtit and both had modifications to the landing gear.
The aircraft did not win the competition, but the second aircraft went on to establish a world record for its class of aircraft of 13,850 ft (4,222 m) over Lympne on 13 October 1923. It is not known what happened to the two aircraft, not having been reported since 1923.