The countries that used the S.M. 79 were:
- S.M.79B: 3
- Engines: Alfa Romeo 128 R.C.18
- S.M.79B: 4
- Engines: FIAT A.80 R.C.41
- S.M.79B: 24
- Engines: Gnôme-Rhône K.14 Mistral-Major
- S.M.79JR: 24
- S.M.79-I: 45
- Exported in 1938.
The S.M.79 was nicknamed the Il Gobbo (the hunchback) due to the gun bulge above the cockpit.
The first S.M.79 made a record breaking flight from Milan to Rome in June 1935.
In September 1935 the S.M. 79 broke six records flying distances of 625 and 1,250 miles while carrying loads from 1,100 lb to 4,400 lb.
Five S.M. 79 Cs flew from Istres to Damascus to Paris on August 20 - 21, 1937 and took 1st through 5th place. The distance was over 4,000 miles at an average speed of 220 mph.
In January 1938 three S.M. 79 Ts flew from Guidonia, Italy, to Dakar and then to Rio de Janeiro, over 6,000 miles / 6,116 miles, at an average speed of 250 mph / 251 mph. The three aircraft were flown by:
- I-Bise: Colonel Attilio Biso, Major Amedeo Paradisi
- I-Moni: Major Nino Moscatelli, Captain Gori Castellani
- I-Brun: Lieutenant Bruno Mussolini, and Lieutenant Renato Mancinelli
Spanish Civil War
The Italians used the S.M.79s in the Aviazione Legionara that fought in the Spanish Civil War. It was first used in February 1937. The 8° and 11° Stormi Bombardamento Veloce were equipped with the SM.79s.
In 1937 the S.M.79-I joined the Regia Aeronautica. It was used as a medium bomber and then a torpedo bomber.
Eleven Stormi were equipped with 389 of the S.M.79-I by 1939.
By June 1940 there were 594 (403 operational) S.M.79-Is with 14 Stomi. They were deployed as follows:
- Italy: 3, 5
- Stormi: 9°, 11°, 12°, 41°, 46°
- Sardinia: 2
- Libya: 3, 4
- Sicily: 2, 5
Royal Navy Loses
The Royal Navy lost four destroyers and had one battleship (HMS Malaya) and three aircraft carriers (Indomitable, Argus, and Victorious) damaged by S.M.79 attacks.
When Italy surrendered there were only 36 airworthy S.M.79s at Capodichino, Littoria, Pisa, and Siena. 34 joined the Allied Co-Belligerent Air Force.
In 1950 three were sold to Lebanon as transports.