Hamburg is on the southern point of the Jutland Peninsula, between Continental Europe to the south and Scandinavia to the north, with the North Sea to the west and the Baltic Sea to the north-east. It is on the River Elbe at its confluence with the Alster and Bille.

The city centre is around the Binnenalster ("Inner Alster") and Außenalster ("Outer Alster"), both formed by damming the River Alster to create lakes. The island of Neuwerk and two small neighbouring islands Scharhörn and Nigehörn, in the Hamburg Wadden Sea National Park, are also part of Hamburg.

The neighbourhoods of Neuenfelde, Cranz, Francop and Finkenwerder are part of the Altes Land (old land) region, the largest contiguous fruit-producing region in Central Europe.

Neugraben-Fischbek has Hamburg's highest elevation, the Hasselbrack at 116.2 metres (381 ft) AMSL. Hamburg, officially Freie und Hansestadt Hamburg, is the second largest city in Germany and the eighth largest city in the European Union. It is also the thirteenth largest German state. It is home to over 1.8 million people, while the Hamburg Metropolitan Region (including parts of the neighbouring Federal States of Lower Saxony and Schleswig-Holstein) has more than 5 million inhabitants. On the river Elbe, the port of Hamburg is the second largest port in Europe (after the Port of Rotterdam) and tenth largest worldwide.

The official name reflects its history as a member of the medieval Hanseatic League, as a free imperial city of the Holy Roman Empire, and that it is a city-state, and one of the 16 states of Germany. Before the 1871 Unification of Germany, it was a fully sovereign state. Prior to the constitutional changes in 1919, the stringent civic republic was ruled by a class of hereditary grand burghers or Hanseaten.

Hamburg is a major transport hub and is one of the most affluent cities in Europe. It has become a media and industrial centre, with plants and facilities belonging to Airbus, Blohm + Voss and Aurubis. The radio and television broadcaster Norddeutscher Rundfunk and publishers such as Gruner + Jahr and Spiegel-Verlag are pillars of the important media industry in Hamburg.

Hamburg has been an important financial centre for centuries, and is the seat of the world's second oldest bank, Berenberg Bank. There are more than 120,000 enterprises.

The city is a major tourist destination for both domestic and overseas visitors; it ranked 17th in the world for livability in 2012, and in 2010 it ranked 10th in the world.