John Peter Didier (1748–1823) was a U.S. politician and the first State Treasurer of Missouri.
John Peter Didier was reportedly a native of France.
Prior to emigrated to the United States, he married Marie Elizabeth Mercier in Besancon, France on November 15, 1773.
A prominent government official in the Missouri Territory, he served as Fire Captain in St. Louis, Missouri from 1811 to 1817.
Public records indicate that he died two years later on August 25, 1823.