The geographical location of Wiesbaden is characterized by the Taunus (southern part of the Rhenish Slate Mountains) and the Mainz Basin (northern section of the Upper Rhine Graben). The city area is located approximately at the coordinates 50° 05' north latitude and 08° 15' east longitude. The southern districts border on the right bank of the Rhine and Main. The city center lies in a basin, which is clearly defined by individual Taunus foothills that extend far into the urban area. The highest elevation in the Wiesbaden Taunus area is the Hohe Wurzel (614 m above sea level), the Schlossplatz in the city center is 115 m above sea level and the lowest point is the Schiersteiner Hafen at 83 m above sea level.

The entire urban area covers around 204 ^km2 and has a population of around 284,600 (as of 31.12.2015). The west-east extension is about 20 km, the north-south direction 18 km. Extensive wooded areas in the north, vineyards in the west and along the River Main as well as agricultural land in the east border the outer districts.

Due to its sheltered location, Wiesbaden enjoys a favorable climate. The average annual temperature is currently around 9.8 °C and the annual rainfall is 638 l/m2. Five valleys carry Taunus water into the Alt-Wiesbaden area. These are, from west to east: the Wellritzbach (Klarenthal or Klarenthaler Straße), the Kesselbach (Adamstal), the Schwarzbach (Nerotal), the Dambach (Dambachtal) and the Rambach. 26 hot springs all come to the surface in the narrow Kochbrunnen area. Where Wilhelmstrasse meets Friedrichstrasse, the aforementioned streams join to form the underground Salzbach (called Rambach up to the Kurpark), which also collects the runoff from the thermal and mineral springs and drains southwards between Biebrich and Amöneburg into the Rhine.

Wiesbaden's most important industrial areas can be found in the southern districts of Biebrich, Schierstein, Amöneburg, Kastel and Kostheim. Large industrial estates have developed in the Äppelallee area between Schierstein and Biebrich as well as in the eastern districts of Erbenheim, Nordenstadt and Delkenheim.

The "Rhein-Main" S-Bahn network links the town to Frankfurt am Main, while other rail connections run along the right bank of the Rhine to Koblenz or via the Ländchesbahn through the eastern suburbs to Niedernhausen with a connection to Limburg. The city is a shareholder of the RMV (Rhein-Main-Verkehrsverbund), which was founded in 1995. Wiesbaden's main railway station is connected to the ICE network and is therefore a long-distance station.

The A 66 highway runs through the southern part of the city in the direction of Frankfurt with a junction to the A 543 to Mainz and the A 671 to Rüsselsheim, from where it continues to Darmstadt. With the A 3, Wiesbaden has a fast connection to Cologne and a further connection to Frankfurt. The federal highways B 54, B 262, B 263, B 417 and B 455 also run through the city area. As the southern parts of the city are located on the Rhine and Main rivers, Wiesbaden is also involved in the north-south transportation of people and goods on the Rhine and to the east in the Main region. Opposite the city of Mainz, south of where the Main flows into the Rhine, is the Mainspitzdreieck. This is where the A 671 and A 60 highways meet.