| Conventional Long Name: | Free State of Anhalt |
| Common Name: | Anhalt |
| Subdivision: | State |
| Nation: | Germany |
| P1: | Duchy of Anhalt |
| Flag P1: | Flagge Herzogtum Anhalt.svg |
| S1: | Saxony-Anhalt (1945-1952) |
| Flag S1: | Flagge_Preu%C3%9Fen_-_Provinz_Sachsen.svg |
| Anthem: | Anhalt Lied "Song of Anhalt" |
| Image Map Caption: | The Free State of Anhalt (red) within the Weimar Republic |
| Capital: | Dessau |
| Government Type: | Republic |
| Title Leader: | Reichsstatthalter |
| Leader1: | Wilhelm Loeper |
| Year Leader1: | 1933 - 1935 |
| Leader2: | Fritz Sauckel |
| Year Leader2: | 1935 - 1937 |
| Leader3: | Rudolf Jordan |
| Year Leader3: | 1937 - 1945 |
| Title Deputy: | Minister-President |
| Deputy1: | Wolfgang Heine (first) |
| Year Deputy1: | 1918 - 1919 |
| Deputy2: | Heinrich Deist |
| Year Deputy2: | 1919 - 1924 |
| Deputy3: | Willy Knorr |
| Year Deputy3: | 1924 - 1924 |
| Deputy4: | Heinrich Deist |
| Year Deputy4: | 1924 - 1932 |
| Deputy5: | Alfred Freyberg |
| Year Deputy5: | 1932 - 1940 |
| Deputy6: | Rudolf Jordan (last) |
| Year Deputy6: | 1940 - 1945 |
| Era: | Interwar / World War II |
| Date Start: | 12 November |
| Year Start: | 1918 |
| Date End: | 23 July |
| Year End: | 1945 |
| Stat Year1: | 1925 |
| Stat Area1: | 2314 |
| Stat Pop1: | 351045 |
The Free State of Anhalt (de|Freistaat Anhalt) was formed after Joachim Ernst, Duke of Anhalt abdicated on 12 November 1918, ending the Duchy of Anhalt. It became a state of Germany under the Weimar Republic (1919–1933) and for most of that time it was led by politicians from the Social-Democratic Party of Germany (SPD).
However, in May 1932, the Nazi Party won the Landtag election and formed a coalition government with its ally, the German National People's Party (DNVP). Following the Nazi seizure of power at the Reich level in 1933, Anhalt, along with all other German states, had its Landtag abolished and its state sovereignty transferred to the Reich government by the "Law on the Reconstruction of the Reich" of 30 January 1934. Though the state itself was not formally abolished, it was superseded in administrative importance by the Nazi Party Gau Magdeburg-Anhalt.
At the end of World War II, when Germany was divided into zones of occupation, Anhalt was merged with the bulk of the Prussian Province of Saxony to form the Soviet-administered German state of Saxony-Anhalt. This state was then dissolved in 1952 but reformed in 1990 after the reunification of Germany.