Albert Carl Grzesinski (born July 28, 1879 in Treptow an der Tollense, Germany as Albert Lehmann, died January 12, 1948 in Queens, New York City) was a German SPD politician and Minister of the Interior of Prussia from 1926 to 1930. Grzesinski was born the illegitimate son of a maid in Berlin and grew up with grandparents. Until he assumed the name of his stepfather in 1892, his name was Lehmann.
He became a member of the SPD in 1897. In 1919, he became Under-Secretary of State in the Prussian War Ministry. He declined the position as Reichswehr Minister (Defense) in 1920. From 1922 to 1924, he was President of the Prussian Police, and from 1925 to 1926, he was President of the Berlin Police.
His tenure as Minister of the Interior was marked by his efforts to promote democracy, and by the political violence in Germany at the time, especially the violence committed by the communists and hostility between the communists and the social democrats. In 1929, he banned the Rotfrontkämpferbund (Red Front Fighter's League) in Prussia.
He resigned on February 28, 1930, for personal reasons. From 1930 to 1932, he was again Police President. In 1931, as Berlin's Police President, he tried to gag Hitler, ordering him deported as an undesirable alien, but Chancellor Heinrich Brüning did not sign the order. He was removed from his position following the 1932 Preußenschlag (Prussian Coup), when he was succeeded by the former Police President of Essen, Kurt Melcher. According to Christopher Clark, he referred to Hiter as 'the foreigner' and found it 'lamentable' that he should be negotiating with the government 'instead of being chased away with a dog whip'. 
Following the Nazi rise to power, and with his name appearing on the first list of Germans, who were arbitrarily officially denaturalised according to a new law, which also ensued the seizure of all his property in Germany, he turned stateless. He fled to Switzerland in 1933. He then emigrated to France, and in 1937, to the United States. In exile, he was active in anti-Nazi organisations.
- Albert Grzesinski: Im Kampf um die deutsche Republik. Erinnerungen eines Sozialdemokraten. Herausgegeben von Eberhard Kolb. München 2001 (Schriftenreihe der Stiftung Reichspräsident-Friedrich-Ebert-Gedenkstätte 9).
- Clark, Christopher (2007). Iron Kingdom: The Rise and Downfall of Prussia, 1600-1947. Penguin. p. 687. ISBN 0140293345.
- Die Ausbürgerung deutscher Staatsangehöriger 1933–45 nach den im Reichsanzeiger veröffentlichten Listen = Expatriation lists as published in the 'Reichsanzeiger' 1933–45:3 vol., Michael Hepp (ed.), Saur. Munich et al. 1985–88, vol. 1: Listen in chronologischer Reihenfolge (1985), Liste 1; ; ISBN 3-598-10537-1