Johann Friedrich Weidler (April 23, 1691 - December 30, 1755) was a German mathematician and legal scholar. Born in Großneuhausen, Weidler enrolled at the University of Jena in 1706 at the age of fifteen. He then enrolled at the University of Wittenburg from which he graduated with a Master's degree in 1712. He was named an adjunct professor at the Philosophical Faculty of the Wittenberg Academy in 1715. He took a break from teaching in 1726 and 1727 and traveled to Holland, England, France, and Switzerland. He received a doctorate in law from a university in Basel in 1727. Weidler then returned to Wittenberg and took a post as an associate professor in the Law School. He published a book based on his mathematics lectures, Institutiones mathematicae, which was published in five editions during his lifetime and several more following his death. Weidler also wrote extensively on astronomy and was named as a foreign member of the Royal Prussian Society of Sciences in 1730.