Well-located hotels of different standards include but are not limited to: IC Hotel Mainz, Hotel Hammer, Hotel Königshof, AC Hotel by Marriott Mainz, and me and all hotel Mainz.
Other options for cheaper monthly room rentals:
List of other options, search platforms, etc. compiled by the City of Mainz:, Airbnb, (rooms in shared apartments), (furnished apartments in Mainz and Wiesbaden), and other larger rental platforms that filter their searches for furnished apartments:,,
In addition, the university might be able to offer a limited number of rooms in two guest houses for students. Negotiations are under way.