Basadingen is a village and former municipality in the canton of Thurgau, Switzerland.
In 1999 the municipality was merged with the neighboring municipality Schlattingen to form a new and larger municipality Basadingen-Schlattingen.
It was first recorded in year 761 as Pasnandingas. However, earlier evidence of settlements includes, finds from the Neolithic period (e.g. on the Buchberg and Dickihof), and a Roman villa with graves in Unterschlatt. In the Early Middle Ages the monasteries of St. Gallen, Rheinau, Reichenau and Allerheiligen owned land in Basadingen. In 1260 the monastery of St. Katharinental bought Reichenau's Kehlhof (a farm owned by a monastery). By 1330 St. Katharinental had acquired many possessions in the village, as well as the low courts right and tithe rights. It became the sole landholder in the village. The high court rights were owned by the bailiwick of Diessenhofen by about 1300. In 1460 the high court transferred to the city of Diessenhofen, which also had the rights to the low court from 1527 until 1798.
During the High Middle Ages the village belonged partly to the parish of Stammheim (today Oberstammheim and Unterstammheim) and partly to the Basadingen parish, which was formed in the 13th Century when St. Martin's Church was built. In 1264, the church was brought under the authority of the monastery of St. Katharinental. After the Protestant Reformation in 1529, the parish of Basadingen and the Basadingen portion of the Stammeheim parish, were merged into a new Basadingen parish, which also included the village of Willisdorf. In 1631 a Catholic parish was established, and St. Martin's Church became a shared church, a condition that remains even today. In 1845 the existing church was dedicated.