Eugen Ott (8 April 1889 – 22 January 1977) was the German ambassador to Japan during the early years of World War II who was notably deceived and compromised by Soviet spy Richard Sorge.

During World War I, Ott served with distinction on the Eastern Front as an officer with the 26th (Württemberg) Infantry Division.

Before Adolf Hitler came to power in Germany (1933), Ott had been the adjutant of General Kurt von Schleicher.

In early September 1940, Heinrich Georg Stahmer arrived in Tokyo to assist Ott in negotiating the Tripartite Pact with Japan.

That trust was the main foundation for Sorge's success as a Red Army spy.