Plauen (German pronunciation: [ˈplaʊən] ^ⓘ; Upper Sorbian: Pławno; Czech: Plavno) is a town in Saxony, Germany with a population of around 65,000. It is Saxony's 5th most populated city after Leipzig, Dresden, Chemnitz and Zwickau, the second-largest city of the Vogtland after Gera, as well as the largest city in the Saxon Vogtland region (Sächsisches Vogtland).

The city lies on the upper reaches of the White Elster River, a tributary of the Saale, in the Central Vogtlandian Hill Country. Plauen is the southwesternmost city of a string of cities sitting in the densely populated foreland of the Elster and Ore Mountains, stretching from Plauen in the southwest via Zwickau, Chemnitz and Freiberg to Dresden in the northeast. It is the county seat of the Vogtland District. Plauen directly borders Greiz in Thuringia to the north, and it is also situated near the Saxon border with Bavaria (Franconia) and the Czech Republic (Bohemia).

Plauen and the surrounding Saxon Vogtland are known as the historic center of the German embroidery and lace industry, and the products of the region are protected under the label Plauener Spitze [de] ("Plauen Lace"). The Elster Viaduct (Elstertalbrücke), spanning the valley of the White Elster between Plauen and Pöhl, is the second-largest bridge built out of bricks in the world, after the Göltzsch Viaduct.

Despite its location in Saxony the regional Vogtlandian dialect spoken in Plauen is a variety of East Franconian (with Saxon influences) related to the dialects of neighbouring Franconia in Bavaria. The name of the city as well as the names of many of its neighborhoods and boroughs are of Slavic origin.

Plauen was founded by Polabian Slavs in the 12th century as "Plawe" and was passed to the Kingdom of Bohemia in 1327. The town was captured by the Archbishop of Magdeburg, Lippold von Bredow [de], in 1384. In 1466, it was passed to Albertine Saxony and later in 1569 to the Electorate of Saxony. Plauen became incorporated into the Kingdom of Saxony in 1806 during the Napoleonic Wars, and in 1871 it became part of the German Empire.

In the late-19th century, Plauen became a centre of textile manufacturing, specializing in Chemical lace, called Plauen lace. Around 1910, Plauen, as an industrial 'boomtown' of the region, reached its population peak (1910 census: 121,000, 1912: 128,000). Plauen's population, however, has shrunk dramatically since the Second World War (1939: 111,000 inhabitants).

In the 1930s, Plauen hosted the first chapter of the Nazi Party outside of Bavaria.

During the war, the Nazis operated a prison in the town, and three subcamps of the Flossenbürg concentration camp. Five hundred women, mostly Polish, but also Russian, Italian, French, Yugoslavian and Croatian, were imprisoned and used as forced labour in the first two subcamps, and 50 men from various countries were imprisoned in the third subcamp. It was occupied by American troops on 16 April 1945 but was left to Red Army on 1 July 1945. On 15 December 1945, the city issued 7 semi-postal postage stamps of its own to raise money for reconstruction.