Helmuth C. H. Wohlthat (4 October 1893 – 1982) was a German businessman and civil servant in Nazi Germany. From 1938, he was a chief aide to Hermann Göring in the Four Year Plan organization, and headed several high-level diplomatic and economic negotiations before and during the Second World War.

Wohlthat was born in 1893 at Wismar and attended the Realgymnasium in Düsseldorf and Berlin. In 1912, he enlisted in the 23rd (2nd Rhenish) Field Artillery Regiment in Koblenz as a Fahnenjunker (officer cadet). In the First World War, he served as an artillery officer and adjutant of the 16th Artillery Brigade, attaining the rank of Oberleutnant. After the end of the war and his discharge from military service, he worked as a commercial trainee and also studied at the University of Cologne. He emigrated to the United States in 1919 and continued his studies in political science at Columbia University. From 1919 to 1933 he worked in New York City as a businessman and trader.

After his return to Germany in 1932, he entered the civil service and worked briefly in the Reich Ministry of Food and Agriculture in the Reich Office of Dairy Products, Oils and Fats. Hjalmar Schacht brought him into the Reich Ministry of Economics and the Prussian Ministry of Economics and Labor in 1934 as a Generalreferent (General Consultant). By December 1934, he had been promoted to Ministerial Director, and in 1935 he became the head of the Reich Office for Foreign Exchange Management. In 1937, he served as the German representative to the London conference that resulted in the 1937 International Agreement for the Regulation of Whaling. On 4 February 1938, when the Ministry of Economics was reorganized under Walther Funk, Wohlthat was named Ministerial Director for Special Projects in Hermann Göring's Four-Year Plan, reporting directly to Göring. At the same time, Göring appointed him to the Prussian State Council.

In his new post, Wohlthat was primarily responsible for foreign trade and foreign exchange management. He also was involved directly in Göring's quest to expropriate Jewish businesses under the policy of Aryanization. Over several months in 1938 he investigated and ultimately exposed the Petschek mining conglomerate to be a Jewish-owned business, despite it being technically controlled by a foreign holding company, and it was ultimately confiscated by government trustees for disposal.

Wohlthat's remit also involved oversight of the German whaling fleet, and he was tasked with planning and preparing for the Antarctic Expedition of 1938-1939. The expedition's main objective was economic, in particular the establishment of a whaling station and the acquisition of fishing grounds for a German whaling fleet to reduce Germany's dependence on imported industrial oils and dietary fats. Preparations took place under strict secrecy, as the enterprise was also tasked with making a feasibility assessment for a future occupation of Antarctic territory. It even resulted in a disputed German territorial claim named New Swabia. The Wohlthat Mountains in Antarctica are named after him.

At this point in his career, Wohlthat embarked on a series of high-level foreign negotiations. In February 1939, he negotiated the Rublee-Wohlthat-Plan with George Rublee, U.S. President Franklin Roosevelt's representative to the Intergovernmental Committee on Refugees. The agreement set out conditions and a funding mechanism (via a trust fund financed by Jewish assets) for the emigration of 150,000 working-age Jews from Germany over a period of 3 to 5 years, to be followed by 250,000 of their dependents. The agreement was never implemented due to the outbreak of the Second World War in September 1939.

Wohlthat's next assignment was as the lead negotiator for the economic treaty with the Kingdom of Romania that was signed on 23 March 1939. By its provisions, Romania agreed to sell 90% of its oil, timber, grains and mineral ores to Germany. This was intended to relieve the Reich's scarcity of food and raw materials. Also, Germany gained the rights to develop additional Romanian oil fields, and was granted lease-free ports on the Danube and Black Sea. All these actions were aimed at securing Romania as a dependent ally in a prelude to the launching of the war. An analysis by Time magazine concluded that the treaty:

… converted Rumania from an independent nation to a German dependency. In no instance of modern times has one State made such humiliating, far-reaching economic concessions to another as Rumania's King Carol II made in Bucharest last week to Dr. Helmuth Wohlthat, Führer Hitler's traveling salesman.