Gustav Albert Peter (21 August 1853, in Gumbinnen – 4 October 1937, in Göttingen) was a German botanist.

In 1874 he received his doctorate from the University of Königsberg, and later on, worked as a curator at the botanical garden in Munich. From 1888 to 1923 he was a professor at the University of Göttingen, where he also served as director of the botanical garden.^[1]

From 1913 till 1919 he collected plants in German South-West Africa, South Africa and especially German East Africa, then later in 1925/26 he was engaged in another botanical expedition in Africa. In 1936 his herbarium of roughly 50,000 plants was acquired by the Berlin-Dahlem Botanical Garden and Botanical Museum.^[2] The plant genus Peterodendron (family Achariaceae) was named in his honor by Hermann Otto Sleumer,^[1] in 1936.^[3]

Peter's daughter Hedwig was married to Leo Rosenberg.^[4]

In the 1890s, he made contributions regarding the plant families Compositae, Convolvulaceae, Hydrophyllaceae and Polemoniaceae to Engler and Prantl's Die Natürlichen Pflanzenfamilien.^[2] With Carl Nägeli he published a two-volume work on the genus Hieracium, titled Die Hieracien Mittel-Europas (Hieracium of Central Europe; 1885–89).^[5] Other noted works by Peter include:

• Flora von Suedhannover nebst den angrenzenden Gebieten (Göttingen, 1901, 2 volumes) – Flora of southern Hanover and adjacent areas.
• Wasserpflanzen und sumpf gewachse in Deutsch-Ostafrika (Berlin, 1928) – Aquatic and marsh plants of German East Africa.
• Flora von Deutsch-Ostafrika (Berlin, 1929–38) – Flora of German East Africa.^[2]