Gostyń dates back to the 13th century. The town was founded by local nobleman and granted town rights in 1278 by Przemysł II. It was named after the nearby village of Gostyń, which since took the name of Stary Gostyń. Administratively part of the Greater Poland Province of the Polish Crown, it developed as a local centre of trade and crafts. In the 16th century Gostyń was an important regional Reformation center, and in 1565 a synod of various Protestants of Greater Poland was held there. The town suffered during the 17th centurySwedish invasions and an epidemic in the 18th-century. In the 18th century one of two main routes connecting Warsaw and Dresden ran through the town at that time and Kings Augustus II the Strong and Augustus III of Poland often traveled that route. In 1793 Gostyń was annexed by Prussia during the Second Partition of Poland. In 1807 regained by the Poles as part of the short-lived Duchy of Warsaw, in 1815 it was re-annexed by Prussia. Gostyń was a center of Polish resistance to Germanisation policies. In 1835 Kasyno Gostyńskie was founded, a significant local Polish organization, which under disguist of social activity conducted economic, educational and library activities. The Prussians abolished the organization in 1846 and its library's collection was moved to Poznań. Gostyń was the site of preparations for the Greater Poland uprising, and during the uprising, it was captured by the Prussians in April 1848. Many inhabitants took part in the next Greater Poland uprising, after which Gostyń joined the re-established Polish state.
During World War II Gostyń was captured by the Werhmacht on September 6, 1939. During the Nazi German occupation of Poland Gostyń became the site of public executions, arrests and expulsions. First mass arrests and executions were carried out already in September 1939. On 21 October 1939 some 30 citizens of the town whose names were listed in the Sonderfahndungsbuch Polen prepared by local German minority, were executed by an Einsatzkommando. Among the murdered were Gostyń's mayor Hipolit Niestrawski, Polish activists, officials, craftsmen and former Greater Poland insurgents. Mass expulsions began on 4 December 1939, with up to 2,000 Poles deported to General Government on the orders of SS-Standartenführer Ernst Damzog stationing in Poznań. Between spring of 1940 and 15 March 1941 additional 3,222 were deported. In 1940 the secret Polish resistance organization was founded. It was crushed by the Germans in 1941. Several dozens of its members were arrested and then brutally tortured in a prison in Rawicz. After a Nazi show trial in Zwickau in 1942, 12 members were executed in Dresden, and several dozen were imprisoned in Nazi concentration camps, where 37 of them died.
