He went from the bathhouse to the doghouse.

A city principal who was removed for several alleged offenses last year — including a staff trip to a notorious Queens spa — is suing to get his job back.

Nadav Zeimer thought he was in the clear last year after an arbitrator exonerated him and directed the city Department of Education to reinstate him as head of Harlem Renaissance HS.

But the DOE has refused, and now Zeimer is taking the city to court.

The DOE brought up Zeimer on several raps — including allegedly forcing staffers to pay for self-help classes, letting his wife volunteer at the school without proper documentation, and sending home kids who showed up to school after 10 a.m.

Zeimer came under fire after taking a group of favored administrators to a seedy Queens bathhouse to foster “professional development.”