His father, Johann Konrad Pfeffel (1682–1738), was the mayor of Colmar and a legal consultant of the French king, but died when Gottlieb was only two years old.

He was raised by his brother Christian Friedrich Pfeffel von Kriegelstein [de] (1726–1807), who was ten years older.

In 1752, Pfeffel translated Johann Joachim Spalding's Gedanken über den Werth der Gefühle in dem Christenthum into French.

[1][2] After the French Revolution, Pfeffel lost the military academy and his fortune, and found jobs with the educational board of Colmar, with the publisher Tübingen-Cotta, and as a translator, until Napoleon I granted him an annual pension in 1806.

[1][2] His poem Der freie Mann was put to music by Ludwig van Beethoven (catalogue number WoO 117) in 1794 or 1795.

[3] Franz Schubert made a lied of his text Der Vatermörder (D10),[4] and Leopold Kozeluch put music to his cantata for the blind Austrian singer Maria Theresia von Paradis.

[6] Pfeffel was a friend or acquaintance of many well-known persons of his period, including Voltaire, Vittorio Alfieri and the Swiss poet Johann Kaspar Lavater, with whom he corresponded for many years.