Already in the Middle Ages there was a prayer room or a synagogue (called 1313). 
 
In the 18th century a prayer hall may have been established again. Until 1855 this was in a building in the Keutelstraße. In the middle of the 19th century, the construction of a new synagogue had become urgently necessary due to the rapidly increasing number of Jewish residents. The community was able to acquire a plot of land "Im Entenpfuhl" in 1854 and presumably began building a new synagogue in the same year. 1855 took place the consecration of the synagogue.  

The New Synagogue Mainz is the successor building to the former main synagogue of the state capital, which was destroyed after the November pogrom in 1938. It was opened on September 3, 2010, and is the community center of the Jewish community of Mainz.

A prayer room was possibly already present since 1815. The location is no longer known. A Jewish prayer room in Rheingönheim is documented in writing in 1859. 
   
On May 15, 1873, the Rheingönheim civic community sold a house at Hauptstraße 67 to the Jewish religious community. The community set up a prayer room and a teacher's apartment in the newly built house. The prayer room was located in the front rooms on the first floor. The teacher's apartment included a living room and kitchen on the first floor and three bedrooms on the 1st floor.  
 

Last use: residential

The exact location of the medieval synagogue (called 1435) is not known. It was probably located in the area of the then Judengasse, where today the Theaterstraße could run.   
  
There was also a synagogue in the 17th century (mentioned in 1684), which was probably destroyed in the great town fire of 1689.   
  
In the 18th century (1742) is mentioned in a council protocol of the city a "Chanteur à la Synagogue". According to this, there was also a prayer room or synagogue at that time.