| Conventional Long Name: | County of Guastalla |
| Common Name: | Guastalla |
| Image Map Caption: | The county of Guastalla (1450) |
| Government Type: | County |
| Year Start: | 1406 |
| Year End: | 1621 |
| Event Start: | Created for the Torelli family |
| Event1: | Partitioned to create Montechiarugolo |
| Date Event1: | 1456 |
| Event2: | Purchased by Ferrante Gonzaga |
| Date Event2: | 1539 |
| Event3: | Reacquired Montechiarugolo |
| Date Event3: | 1612 |
| Event End: | Raised to duchy by Ferdinand II |
| Date End: | 2 July |
| P1: | GuastallaLordship of Guastalla |
| Flag P1: | Blason famille Torelli.svg |
| S1: | Duchy of Guastalla |
| Flag S1: | Arms of Ferrante II Gonzaga, Duke of Guastalla.svg |
| Border S1: | no |
| Capital: | Guastalla |
| Religion: | Roman Catholicism |
| Currency: | Guastalla lira |
| Title Leader: | Count |
| Year Leader1: | 1406–1449 |
| Year Leader2: | 1575–1621 |
| Today: | Italy |
The County of Guastalla was an Italian state, centered on the city of Guastalla in Northern Italy, which existed from 1428 to 1621, when it was then elevated to a Duchy.
The title of count was conferred in 1428 on Guido Torelli for the services rendered to the Duke of Milan, Filippo Maria Visconti.[1] His descendants maintained the regency of the territory until 1539, when, finding themselves in financial straits, the family was forced to sell their domains, purchased by Ferrante Gonzaga. From that moment Guastalla significantly increased its prestige. Gonzaga was in fact one of the most influential men of his time, from a political and military point of view. When he died in 1557, his inheritance passed to his firstborn Cesare I Gonzaga, who definitively established his court in Guastalla in 1567. Many works such as the church, the mint, Via Gonzaga and the completion of the ducal palace were built by him. In 1575 he was succeeded by his son Ferrante II.[2]
Another branch of the Torelli family from Guastalla ruled the County of Montechiarugolo (separated from the county of Guastalla in 1456) until 1612.[3]