Friedrich Alexander Maria Mandl colloquially Fritz Mandl (9 February 1900 – 8 September 1977) was an Austrian industrialist, armament manufacturer, private investor and prominent fascist. He would be known as the King of Ammunition for leading the Hirtenberger ammunition concern.

Mandl was closely associated with Austrofascism, Fascist Italy as well as an opponent of Nazism. In the 1930s, he became an ally of Prince Ernst Rüdiger Starhemberg, then commander of the Austrian nationalist militia ("Heimwehr"), which he furnished with weapons and ammunition. He was once the richest Austrian.

Mandl was born 9 February 1900 in Vienna, Austria-Hungary, the older of two children, to Alexander Mandl (1861–1943), an armament manufacturer, and Maria Mandl (née Mohr; 1873–1924). He had a younger sister, Renata Renée Ferro (née Mandl; 1901–1985).

His mother was Roman Catholic, his father was Jewish. In 1910, the family converted fully to Christianity. He completed high school at the Piaristengymnasium in Krems. During World War I, aged 18, he served one year as volunteer soldier, followed by chemistry studies.

In 1921, the Hirtenberger Ammunition Factory, supplied Poland with military goods during the war against Soviet Russia, leading to the factory being set on fire by communist workers. Additionally, the factory faced challenges throughout the 1920s due to the ban on weapons exports stipulated by the Treaty of Saint-Germain.

Mandl found ways to circumvent these obstacles. By 1924, he was managing the factory and became its general director in 1930. Later, he also became the owner of the Lichtenwörther Ammunition Factory and the Grünbach coal mines. In 1928, Mandl represented the Hirtenberger Ammunition Factory as the Austrian partner in a joint venture in Solothurn, Switzerland. The other partner was the large corporation Rheinmetall, the second-largest German arms manufacturer after Krupp, represented by weapons engineer Hans Eltze. The Solothurn weapons factory was used as a cover for the export of German and Austrian weapons, particularly anti-tank and anti-aircraft guns, under a Swiss label.

Mandl's empire stretched across several countries. He essentially had a monopoly on ammunition supplies to Italy. In Poland, he acquired a factory as compensation for the supplies provided during the Polish-Soviet War. He also owned an arms factory in Dordrecht, in southern Holland. In 1938, Mandl attempted to establish a munitions factory for the Portuguese War Ministry, but the pro-German lobby within the ministry opposed any agreement with the "Jew" Fritz Mandl and favored partnerships with German companies like Fritz Werner AG.

The failure of this venture marked the slow decline of Mandl’s political ties with fascist regimes, which began to lean toward Nazi Germany. Even his friend Mussolini could no longer be relied upon. His protege Starhemberg, too, showed no gratitude, publishing a memoir in which Mandl played no role. Despite these setbacks, Mandl continued to try to improve his relations with Nazi Germany. He claimed that his involvement in the Austrofascist militia was not directed against the German Anschluss but rather against the socialists. He also spread the story that he was the son of an extramarital affair between his mother and a Catholic bishop, and thus not Jewish. Ultimately, he called on the workers at the Hirtenberger Ammunition Factory to vote in favor of the Anschluss.