Friedrich Julius Stahl, German constitutional lawyer, political philosopher and politician.

Friedrich Johann Justin Bertuch was a German publisher and patron of the arts. He co-founded the Weimar Princely Free Drawing School with the painter Georg Melchior Kraus in 1776. He was the father of the writer and journalist Karl Bertuch.

Friedrich Kaiser was an Austrian playwright. During his youth he was one of the most popular people in Vienna. Some of his plays were "Hans Hasenkopf" (1835); "Wer wird Amtmann" (1840), "Palais und Irrenhaus" (1863), "Des Krämers Töchterlein" (1862), "Pater Abraham a Sancta Clara" as well as many others. He also wrote the historical novel "Ein Plaffenfeben."

Friedrich Karl Hermann Kruse was a German historian born in Oldenburg.

Friedrich Karl Kasimir von Creutz was a German poet, philosopher, writer and politician. He was born in Bad Homburg, where he also died, and was a councillor and ally of Frederick V, Landgrave of Hesse-Homburg.

Friedrich Kauffmann was a German philologist who specialized in Germanic studies.

August Friedrich Kellner was a German mid-level official and diarist who worked as a justice inspector in Laubach from 1933 to 1945.

Heinrich Friedrich Theodor Kohlrausch was a German educator and historian.

Friedrich Konrad Müller was a German poet, journalist and physician. He called himself Müller von der Werra.

Friedrich Ludwig "Fritz" Bauer was a German pioneer of computer science and professor at the Technical University of Munich.