Joseph Ignatz Sadler (17 February 1725 - 9 January 1767) was a Czech painter.
Sadler was born in Olomouc, and primarily painted religious-themed frescoes.
acting especially in Moravia, for example the frescoes on the ceiling of the church of the Most Holy Trinity Church, Fulnek.
He was the brother-in-law of the painter Johann Christoph Handke.