The bath complex was built between 1912 and 1918 in the (Secession) Art Nouveau style. It was damaged during World War II but then rebuilt. References to healing waters in this location are found from as early as the 13th century. A hospital was located on this site during the Middle Ages. During the reign of the Ottoman Empire, baths were also built on this particular site. The "magical healing spring" was used by the Turkish during the 16th and 17th centuries. The bath was called Sárosfürdő ("muddy" bath) because the mineral mud settled at the bottom of pools.

The Gellért Bath underwent its first extensive renovation in 2008. The bath closed only once in its almost century-long existence due to a burst pipe. The Gellért was open even during World War II. Towards the end of the war, the prestigious Art Nouveau women's thermal bath was bombed, destroying the Zsolnay pyrogranite façade and the wooden interior of the dressing rooms. Due to economic condition following the war, the thermal bath was redesigned in a much more puritanical manner. The 2008 reconstruction served to restore the bath to its original splendor.