Salmsach is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.HistorySalmsach is first mentioned in 1155 as Salmasa. Salmsach was probably founded by the Bishop of Constance Salomo I who founded a religious community there. It was placed under the Abbey of St. Stephen in Constance by Salomo III in 910. In 1155 the abbey owned a farm, five Schupposen, some tithe rights and half the church treasure in Salmsach. In 1380 it acquired at least the low justice rights as well. The Abbot of St. Gall, Ulrich Rösch, acquired Salmsach and the church treasure in 1471 and united it with the court of Romanshorn. They remained united until 1798. (to 1798). The Knights of the Churchyard of Arbon, who had entered into a contract in 1201 with provost and the Abbey of St. Stephen, were allowed to appoint the pastor and had other rights in the village. During the Protestant Reformation, Salmsach converted to the new religion. After 1588, the pastor of Salmsach also held services in Romanshorn. In 1917, Salmsach merged with the parish of Romanshorn.In 1742 a school was founded in both Salmsach and Hungerbüel. The village of Hungerbüel merged with Salmsach in 1812.