Neukölln (nɔʏˈkœln; formerly Rixdorf), until 1920 an independent city, is a large inner-city quarter (Ortsteil) of Berlin in the homonymous borough (Bezirk) of Neukölln, including the historic village of Alt-Rixdorf and numerous Gründerzeit apartment blocks. With 166,714 inhabitants (2018) the Ortsteil is the most densely populated of Berlin. It was originally characterized by mostly working-class inhabitants and later a relatively high percentage of immigrants, especially of Turkish and Russian descent, but since the turn of the millennium an influx of students, creatives, and western immigrants has led to gentrification.
Neukölln lies on the geological border between the shallow Berliner Urstromtal glacial valley and the Tempelhofer Berge, which are situated in the northernmost region of the Teltow ground moraine plateau, rising to the south of Hermannplatz, in what is mostly the typical low-lying marshy woodlands with a mainly flat topography of the North European Plain.
The quarter is situated south-east of the Berlin city center, in the north of the Neukölln borough, adjacent to the quarter of Kreuzberg (in the Friedrichshain-Kreuzberg borough) at the Landwehrkanal, and the streets Hasenheide and Kottbusser Damm. It also borders with the quarters Alt-Treptow, Plänterwald and Baumschulenweg (all part of Treptow-Köpenick) in the east, and Tempelhof (in Tempelhof-Schöneberg) in the west, separated by the parks Volkspark Hasenheide and Tempelhofer Feld, the vast field of the former Tempelhof Airport, now a popular recreation area. In the south, the Stadtring motorway and the Neukölln Ship and Britz canals form the border with the Britz and Baumschulenweg quarters.
Neukölln is divided into nine official neighborhoods (Kieze or Stadtquartiere, officially called Ortslagen), among them the historical sites of Neukölln's foundation south-east of the quarters's geographical center, Richardplatz-Süd to the north-west, and Böhmisch-Rixdorf to the south-east, which together are commonly referred to as Rixdorf or Alt-Rixdorf ("Old Rixdorf").