Johann Gottlob Töpfer (1791–1870) was a German organ theorist, advisor, organist, teacher and composer.

In 1830 he was appointed organist at the city church of Saint Peter and Paul at Weimar.

He held this post until his death, despite attempting to resign in 1844 because of unreasonable conditions; he withdrew his request later.

His definition of a Normalmensur is still used today as a basic reference-point for calculation and description of the scaling of organ pipes.

Töpfer's publications in 1833, 1843, and 1855 were widely influential because they appeared at a time when the French and English organ makers were open to new, foreign ideas, and they gave full details of pipe scales, wind chambers, pallets, bellows and action.