| Conflict: | Uprising in West-Hungary |
| Date: | 28 August - 13 October 1921 |
| Place: | West-Hungary (Sopron County, Moson County, Vas County) (today part of: Burgenland, Austria and Hungary) |
| Casus: | Treaty of Saint-Germain-en-Laye Treaty of Trianon |
| Territory: | Sopron and its area remained in Hungary |
| Result: | Hungarian victory, referendum called |
| Combatant1: | Austria Hungary (disarmament of the rebels in 1922) Czechoslovakia (small border conflicts) France (Non-combatant military mission) |
| Combatant2: | Rongyos Gárda Lajtabánság Bosnian and Albanian Muslim volunteers |
| Commander1: | Johannes Schober Robert Davy Anton Petzt Rudolf Plenert |
| Commander2: | Pál Prónay Iván Héjjas Gyula Ostenburg-Moravek Mihály Francia Kiss Károly Kaszala István Friedrich Gyula Gömbös Huszein Durics Hilmi |
| Strength1: | ~500 Austrian police officers and gendarmeries |
| Strength2: | ~500-600 |
| Casualties1: | 12 killed 46 wounded |
| Casualties2: | 24 killed |
According to the Treaty of Trianon, the city of Sopron in western Hungary and its surroundings were assigned to Austria. After an uprising in 1921 in this region, a referendum was held and 65.08% of the votes were in favor of belonging to Hungary. This referendum was accepted by the major powers and the transition of Sopron and its surrounding 8 villages from Austria to Hungary was the only serious territorial revision in the years following the Treaty of Trianon.