Limburg an der Lahn (officially abbreviated Limburg a. d. Lahn) is the district seat of Limburg-Weilburg in Hesse, Germany.
Limburg lies in western Hessen between the Taunus and the Westerwald on the river Lahn.
The town lies roughly centrally in a basin within the Rhenish Slate Mountains which is surrounded by the low ranges of the Taunus and Westerwald and called the Limburg Basin (Limburger Becken). Owing to the favourable soil and climate, the Limburg Basin stands as one of Hesse's richest agricultural regions and moreover, with its convenient Lahn crossing, it has been of great importance to transport since the Middle Ages. Within the basin, the Lahn's otherwise rather narrow lower valley broadens out noticeably, making Limburg's mean elevation only 117 m above sea level.
Limburg forms, together with the town of Diez, a middle centre (in terms of Central place theory) but partially functions as an upper centre to western Middle Hesse.
Limburg's residential neighbourhoods reach beyond the town limits; the neighbouring centres of Elz and Diez run seamlessly together.
Surrounding towns and communities are the community of Elz and the town of Hadamar in the north, the community of Beselich in the northeast, the town of Runkel in the east, the communities of Villmar and Brechen in the southeast, the community of Hünfelden in the south (all in Limburg-Weilburg), the community of Holzheim in the southwest, and the town of Diez and the communities of Aull and Gückingen in the west (all in the Rhein-Lahn-Kreis in Rhineland-Palatinate).
The nearest major cities are Wetzlar and Gießen to the north east, Wiesbaden and Frankfurt to the south and Koblenz to the west.
The town consists of eight formerly autonomous Ortsbezirke or boroughs, listed here by population (as of 2020):
Limburg: 19,401
Lindenholzhausen: 3,315
Linter: 3,080
Eschhofen: 2,789
Staffel: 2,762
Offheim: 2,608
Dietkirchen: 1,630
Ahlbach: 1,252
Each Ortsbezirk is represented by a council.