John Messinger (January 4, 1771 – September 16, 1846) was an American pioneer, politician, teacher, and surveyor who was the first Speaker of the Illinois House of Representatives.
When the state of Illinois was created in 1818, he co-authored its constitution and served in its first General Assembly as Speaker of the House.
He held a number of jobs in Vermont including carpenter, builder, teacher, mill-wright, and farmer.
At the time, Lyon was being persecuted via the Alien and Sedition Acts so he decided to move, with Messinger, to Kentucky near the mouth of the Cumberland River.
Lyon became a prosperous slave trader, but this irked anti-slavery Messinger and his brother-in-law George Cadwell.
Cadwell and Messenger moved to the Indiana Territory in 1802, settling near New Design in what is now Monroe County, Illinois.