Friedrich Ludwig Weidig (15 February 1791 - 23 February 1837) was a German Protestant theologian, pastor, activist, teacher and journalist. Initially working as a teacher in Butzbach, he then spent a short time as a pastor in Ober-Gleen, a district of Gießen. In what is now Hesse and the Middle Rhine, he was one of the main figures of the Vormärz and a pioneer of the 1848 Revolution.
Weidig was born in the Oberkleen district, Langgöns, northwest of Wetterau.
The son of a chief forester and his wife, her maiden name being Liebknecht. He went to Butzbach in 1803 to go to school. During his theological studies in the Ludoviciana in Gießen he was a member of the 'fränkischen Landsmannschaft'. In 1812 he became headmaster at the boys' school in Butzbach. Following Friedrich Ludwig Jahn's example, Weidig taught his pupils drill and physical exercise and in 1814 founded a parade ground on the Schrenzer, a north-eastern foothill of the Taunus - later historians and biographers thus called him the "father of Hessian drill".
From 1818 Weidig was monitored by the authorities for his political activities in teaching, preaching and in private - he was one of the liberal democrats who aspired to establish Germany as a unified democratic nation state. In 1832 he thus travelled to south-west Germany and helped in the preparations for the Hambach Festival.
In 1833 Weidig was arrested for the first time, but in 1834 he still published four illegal issues of "Leuchter und Beleuchter für Hessen (oder der Hessen Notwehr)". The same year saw his first meeting with Georg Büchner, with whom he worked on a manuscript that Weidig then published against Büchner's wishes as Hessischen Landboten. Weidig and his students also organised the printing and distribution of illegal pamphlets.