The Aero A.23 was a Czechoslovakian biplane airliner of the 1920s. Aero's previous airliner design, the A.10 had been a relatively crude machine drawing heavily on World War I military aircraft. The A.23, designed in 1925 was relatively modern, although it still seated its pilot in an open cockpit above the passenger cabin. Seven A.23s flew CSA's Prague-Marienbad (Mariánské Lázně) and Prague-Uzhhorod routes between 1926 and 1936.