Hans Paul Oster (9 August 1887 – 9 April 1945) was a general in the Wehrmacht and a leading figure of the anti-Nazi German resistance from 1938 to 1943.

After the failed 1944 July Plot on Hitler's life, during interrogation, he named Admiral Wilhelm Canaris, the head of Abwehr, as the "spiritual founder of the Resistance Movement".

[1] He entered the artillery in 1907 and in World War I, he served on the Western Front until 1916, when he was appointed as captain to the German General Staff.

However, his opinion changed after the 1934 Night of the Long Knives in which the Schutzstaffel (SS) murdered many of the leaders of the rival Sturmabteilung (SA) and their political opponents, including General Kurt von Schleicher, the second-to-last Chancellor of the Weimar Republic and Generalmajor (Major General) Ferdinand von Bredow, former head of the Abwehr.

In August 1938, Beck spoke openly at a meeting of army generals in Berlin about his opposition to a war with the Western powers over Czechoslovakia.

However, the army generals argued that they could mobilise support among the officer corps only if Hitler made overt moves towards war.

Emissaries of the conspirators travelled to Britain, with the assistance of Oster and the Abwehr, to urge the British to stand firm against Hitler over the Sudeten crisis.

On 28 September, the British Prime Minister Neville Chamberlain agreed to a meeting in Munich, where he accepted the dismemberment of Czechoslovakia.

However, many officers, particularly those from the Prussian Junker background, were strongly anti-Polish and saw a war to regain Danzig and other lost eastern territories as justified.

When Hitler decided to attack France soon after the Polish campaign in 1939, Halder along with other senior generals, thought it to be hopelessly unrealistic and again entertained the idea of a coup, urged by Oster and Canaris.

[13] On 8 April 1945, Oster, Dietrich Bonhoeffer, Wilhelm Canaris, and other anti-Nazis were convicted and sentenced to death by an SS drumhead court-martial presided over by Otto Thorbeck.

[14] Fabian von Schlabrendorff, one of the few senior anti-Nazis to survive the war, described Oster as "a man such as God meant men to be, lucid and serene in mind, imperturbable in danger".