The Blériot-SPAD S.61 was a French fighter aircraft developed in 1923. Designed by André Herbemont, the S.61 was a conventional biplane, abandoning the swept upper wing used by Herbemont in several previous designs. The prototype S.61 was evaluated by the French Air Force alongside the S.51 as a potential new fighter, but like its stablemate, was rejected. The Polish Air Force (which had also purchased the S.51) was impressed enough to order 250, as well as purchase licences for local production. The Romanian Air Force also ordered 100 aircraft. About 30 were built in Poland, by the CWL (Centralne Warszaty Lotnicze - Central Aviation Workshops, a predecessor of PZL).
Apart from their military service, S.61s were used in France for racing and record-setting attempts. On 25 June 1925, Pelletier d'Oisy won the cross-country Coupe Michelin in an S.61, and another of the type won the 1927 competition and was placed second in 1929. An S.61 was also used by Jean Callizo in his fraudulent attempt on the world altitude record that saw him stripped of his Légion d'Honneur. A Polish S.61 placed second in the Capitaine Echard race at the Zürich aerial meeting in 1927.