Findings from the Neolithic period prove the early existence of a settlement in the area where Feldbach is now located. The name "Feldbach" was first mentioned in 1188 as "Velwinbach". A parish exists since 1232.
In 1469, Feldbach was devastated by rebellious troops. This is probably the reason why the Feldbach Tabor (de), a medieval fortress, was built.
In the 15th century, Feldbach was the setting of many conflicts between rival aristocratic families which caused destruction and pillages in the town. Finally, after the Hajduks (which accompanied the attacking Ottoman Turks) destroyed the whole town, except the Tabor hill, a closed fortification with several gates was built.
Feldbach experienced a major economic upswing after the Hungarian Western railroad was opened in 1873. At the same time the nearby spaBad Gleichenberg became well known.