Ernst Deger (15 April 1809, Bockenem – 27 January 1885, Düsseldorf) was a German religious artist, in the style of the Nazarene movement. He is considered to be the main representative of Christian art in the Düsseldorfer Malerschule.
He began his studies in 1828, at the Berlin Art Academy, then moved to the Kunstakademie Düsseldorf, where he studied with Wilhelm von Schadow. From 1834 to 1835, he was a student in the Master Class. On behalf of the (Artists' Association), he created an altarpiece for the Church of St. Andreas, showing Mary as the Queen of Heaven. Following its unveiling in 1837, it became one of the region's most popular religious images and found its way into numerous Catholic prayer books as a small andachtsbilder (devotional image). A notable feature is its depiction of Jesus as a toddler, rather than an infant.
From 1837 to 1842, he travelled through Italy. After his return, on behalf of Count Franz Egon von Fürstenberg-Stammheim, he worked with Karl Müller, Andreas Müller and Franz Ittenbach, creating frescoes of scenes from the life of Christ at the Apollinariskirche, Remagen. This project kept him occupied until 1851.
His next major project, commissioned by King Frederick William IV of Prussia, involved a series of wall paintings at Stolzenfels Castle. During its final phases, he was assisted by Peter Molitor, a struggling young artist from Koblenz. This has come to be considered his most important work.
In 1860, he began teaching at his alma mater, the Kunstakademie. He was appointed Professor of religious history painting in 1869. His best-known students included and Friedrich Stummel. Many of his works have been widely distributed through reproductions.