Albert Maria Forster (26 July 1902 – 28 February 1952) was a German Nazi Party politician, member of the SS and war criminal. During the Second World War, under his administration as the Gauleiter and Reichsstatthalter of Danzig-West Prussia (the other German-annexed section of occupied Poland aside from the Warthegau), the local non-German populations of Poles and Jews were classified as sub-human and subjected to extermination campaigns involving ethnic cleansing, mass murder, and in the case of some Poles with German ancestry, forceful Germanisation. Forster was directly responsible for the extermination of non-Germans and was a strong supporter of Polish genocide, which he had advocated before the war. Forster was tried, convicted and hanged in Warsaw for his crimes, after Germany was defeated.

Forster was born in Fürth, where he attended Volksschule and the Humanistisches Gymnasium from 1908 to 1920. He then trained in banking for two years and began working at a Fürth bank in 1922. In November 1923, he joined the Nazi Party, becoming the leader of its local branch in Fürth; he also became a member of the SA at that time. In May 1924 he was dismissed from the bank for his Nazi activities, including antisemitic agitation. Following the Beer Hall Putsch when the Nazi Party was outlawed, he became a member of a Nazi front organization, the Greater German People's Community, and served as its local leader. During this time he was befriended by Julius Streicher, the Party leader of northern Bavaria, and became a part-time journalist for Streicher's weekly antisemitic paper Der Stürmer. He was a spectator of the treason trial of Adolf Hitler, Erich Ludendorff, and eight others putschists from 26 February to 1 April 1924 in the Munich court.

Forster was in attendance in Munich when the Nazi Party was refounded by Hitler on 27 February 1925, and he again became the Ortsgruppenleiter (Local Group Leader) in Fürth. He officially rejoined the Party on 5 April 1925 (membership number 1,924); as an early Party member he was considered an Alter Kämpfer and would later be awarded the Golden Party Badge. He soon became a Parteiredner (Party orator) giving speeches throughout the area. On 12 May 1926, he joined the Schutzstaffel (SS), forming and leading the SS Group "Nurnberg-Fürth" in July 1926. From February 1928, Forster was employed as a payment office official by the German National Association of Commercial Employees (Deutschnationaler Handlungsgehilfen-Verband, DHV), a nationalist and anti-Semitic trade union. Forster unsuccessfully sought a seat in the Reichstag at the 20 May 1928 election. However, that year he advanced to Party Bezirksleiter (District Leader) for Middle Franconia, while also retaining his leadership in Fürth; he would continue to hold these positions through December 1929. At the 14 September 1930 election, Forster was elected to the Reichstag from electoral constituency 26, Franconia, the seat he would retain until July 1940. He was made the expert advisor on labor and clerical employee issues to the Nazi Reichstag faction. When elected, he was the youngest deputy in the Reichstag.

On 15 October 1930, Forster became the Nazi Party's Gauleiter of the Free City of Danzig (now Gdańsk, Poland), replacing Arthur Greiser who then became the Deputy Gauleiter. This touched off a feud between them and Greiser was to remain Forster's lifelong nemesis. Many residents resented Forster as an interloper who had replaced Greiser, a native Danziger. Forster immediately embarked on an aggressive propaganda campaign and membership drive. In November 1930, he became the founder and publisher of the Danziger Beobachter (Danzig Observer). From December 1930 to December 1932, he increased the Danzig Party membership from 1,310 to 9,519, and the local SA from 150 to 1,500 members.

After the Nazi seizure of power, Forster spearheaded the Nazi takeover of Danzig in spring 1933, attaining an absolute majority for the Nazi Party in the Danzig Senate. Hitler rewarded him with the leadership of the DHV on 10 May 1933, making him the head of all clerical employee organizations within the German Labor Front. On 15 September he was appointed to the Prussian State Council and in January 1934, he was made honorary Führer of the 36th SS-Standarte in Danzig. In January 1935, he was named chairman of the Danzig branch of the Nordische Gesellschaft (Nordic Society) charged with strengthening German-Nordic cultural and political cooperation. On 23 January 1936, he became a member of the personal staff of Reichsführer-SS Heinrich Himmler.

In 1937 Forster boasted about his fight against communists and other "subhumans".

In 1939, following orders from Berlin, Forster led the agitation in Danzig to step up pressure for annexation by Nazi Germany and proclaimed that in future "Poland will be only a dream". On 23 August Forster replaced Greiser as Danzig's head of state. The Danzig issue was one of the pretexts used for the Nazi invasion of Poland in 1939. He was hateful of Jews whom he called "dirty and slippery race" and he expressed his desire to control parts of Poland after Poles would be expelled from them.

Before World War II, Forster had tried and failed to gain control over the organisation of the irredentist activities of the ethnic German population in the Polish Corridor neighbouring Freie Stadt Danzig, which was created in 1920 by the Treaty of Versailles; rather it was the SS-dominated Volksdeutsche Mittelstelle that won control. With Forster and Himmler engaged in a power struggle, this rendered the (ethnic) Germans suspicious of Forster. When these territories were annexed after the Invasion of Poland and they became Reichsgau Danzig – West Prussia, Forster's distrust of the local Nazi leaders led him to deny them political power. Forster filled all the significant positions with his allies from the pre-war Free City of Danzig. This snub provoked bitterness among the local Germans in addition to Forster's Germanisation policies, which denied them a higher status than local Poles.