Friedrich Ritter (9 May 1898 – 9 April 1989) was a German botanist who collected and described many species of cacti.
Friedrich Ritter studied biology, geology and paleontology at the University of Marburg.
During this time he began to deal more intensively with cacti.
From 1930 he undertook study trips to Peru, Bolivia, Argentina, Brazil and Chile.
From the end of 1976 he lived again in Germany with his sister in Spangenberg near Kassel.