Kārlis Augusts Vilhelms Ulmanis (Latvian: [ˈkaːrlis ˈɑuɡusts ˈvilxɛlms ˈuɫmɑnis]; 4 September 1877 – 20 September 1942) was a Latvian politician and a dictator. He was one of the most prominent Latvian politicians of pre-World War II Latvia during the Interwar period of independence from November 1918 to June 1940 and served as the country's first prime minister.

He served four times as prime minister, the last time as the head of an authoritarian regime, during which he subsequently also adopted the title of President of Latvia. The legacy of his dictatorship continues to divide public opinion in Latvia today.