Dirmstein (Palatine German: Dermschdää) is an Ortsgemeinde – a municipality belonging to a Verbandsgemeinde, a kind of collective municipality – in the Bad Dürkheim district in Rhineland-Palatinate, Germany. With its roughly 3,000 inhabitants, it is the third largest Ortsgemeinde in the Verbandsgemeinde of Leiningerland, whose seat is in Grünstadt, although that town is itself not in the Verbandsgemeinde. Dirmstein lies in the outermost northeast of the district and the northwest of the Rhine-Neckar urban agglomeration.

In the 8th century, Dirmstein had its first documentary mention, although this was undated. The first dated documentary mention came in 842. Although it never belonged to the Counts of Leiningen, it is today counted as part of the Leiningerland, the name used for those noblemen's old domain. The historical and well restored village centre has been raised to a monumental zone by the monument protection authority. Of the 58 protected objects, 48 lie within this zone. With few exceptions, they go back, like the village's foremost landmark, the Baroque simultaneous church St. Laurentius (Saint Lawrence's), to the municipality's heyday in the 18th century, towards the end of which Dirmstein apparently held town rights for two decades, although some sources are disputed.

Dirmstein lies at an elevation of 108 m above sea level on the Upper Rhine Plain in the northeast Palatinate. Twelve kilometres to the east (as the crow flies) flows the Rhine, while 9 km to the west begins the Palatinate Forest and 2 km to the north runs the boundary with the neighbouring region, Rhenish Hesse.

Clockwise from the north, these are Offstein and Worms-Heppenheim (both in Rhenish Hesse) to the north, Heuchelheim (Verbandsgemeinde of Heßheim) in the east and Gerolsheim, Laumersheim and Obersülzen (all in the Verbandsgemeinde of Leiningerland) in the south, southwest and west. Heppenheim lies 5 km away, Offstein 4 km and each of the others 2 km.

Towards the eastern end alongside the Rhine, the municipal area is quite even, rising to considerable hills in the west. These belong to the Palatinate wine region between the plain and the low mountain range, which here, until 1969, was known as Unterhaardt, but which now bears the name Mittelhaardt-Deutsche Weinstraße.

The municipal area is crossed from west to east by the river Eckbach, which flows into the municipality in the southwest, from Laumersheim. In the 1920s, it was redirected from the village centre to the southern outskirts. Until this time, there had been a flat, pondlike broadening of the brook's bed south of the church on the Affenstein (a street), next to the village thoroughfare in which carriages could be cleansed of sand and loam buildup. As a new riverbed (going straight ahead instead of left), the old channel left over from the old "Upper Village’s" mediaeval fortification dyke seemed an obvious choice. Between the "Upper" and "Lower Village", today's Eckbach meets its old course again coming from the right.

The in itself unimposing river Floßbach, coming from Obersülzen and also known locally as the Landgraben, which flows round Dirmstein in the north and on the village's eastern outskirts empties into the Eckbach from the left, was in the latter half of the 20th century straightened. The loss of flooding areas thus wrought, together with the increased speed of flow, brought about problems in times of heavy rainfall for the Nördlich der Heuchelheimer Straße ("North of Heuchelheim Road") construction site opened in the 1980s. In 1994 came widespread flooding for the first time, in which basements were filled with water up to their upper edges. In 2006, various versions of a plan to create flooding areas were brought forth for discussion. In 2008, Grünstadt-Land Verbandsgemeinde council decided to renaturate the brook over a stretch of a good kilometre. As an ecologically worthy measure, it was subsidized by the state of Rhineland-Palatinate to a share of 90% of the cost within the framework of its Aktion Blau. In October 2008, the conversion began, in which former cropland along the brook, which through Flurbereinigung had been transferred to the municipality's ownership, was removed so that the brook could broaden out to the sides in heavy rains. To reduce the speed of flow, meanders were built back in and, of particular importance, two almost right-angled bends were smoothed out. With the planting of typical local trees and shrubs, the renaturation was completed in early 2009.

The most important event in the eastern Palatinate's geological development was the rifting and downfaulting relative to the surrounding low mountains of the Upper Rhine Plain, whose onset was some 65,000,000 years ago in the Lower Tertiary and which has lasted until today. Before the mountains spread an area that was over time scored by the Eckbach and Floßbach. During the ice ages, there were gradual solifluction on the slopes and also wind abrasion in great parts of Europe. These processes led to a transformation of the original surface relief in whose wake a floodplain with embanked or eroded terraces formed. In colder, drier phases of the Würm glaciation, loess beds came into being through the influence of the wind, whereby the loess gathered mostly at faults and alee of small hollows. Later erosion created steep banks in the loess areas, which today can reach 6 m in height and are valuable biotopes.