Operators
- Germany
- Luftwaffe
- Aufklärungsgeschwader 53
- Aufklärungsgeschwader 54
- Erprobungstelle 61
- Leichtes Kampfgeschwader 41
- Leichtes Kampfgeschwader 42
- Leichtes Kampfgeschwader 43
- Leichtes Kampfgeschwader 44
- Waffenschule 50
- Greece
- Hellenic Air Force Evaluation operator, four aircraft in service, but retired.
- Italy
- Italian Air Force
- Frecce Tricolori
- Portugal
- Portuguese Air Force (1966–1993)
- USA
- United States Army – Evaluated two aircraft (1 G.91R/1, 1 G.91R/3) in 1961.
- United States Air Force – Also an evaluation operator, two aircraft served.
Read more about this topic: Fiat G.91