Edward Dufner, a son of immigrants from Baden, Germany, received his first art instruction when he was about fifteen years old; he exchanged his services doing odd jobs in the office of the architect Charles Sumner for lessons in perspective drawing. He later worked as an illustrator for a German-language newspaper in Buffalo. Dufner began attending evening classes under George Bridgman at the Buffalo Fine Arts Academy in 1890. At the end of three years of study he was awarded the school's Albright scholarship for a year of study at the Art Students League in New York; there he worked under Henry Siddons Mowbray. He then found work illustrating magazines such as Life, Harper's, and Scribner's.
Dufner departed for Paris in 1898 and spent the next five and a half years abroad. He studied with Jean-Paul Laurens at the Académie Julian and privately with James Abbott McNeill Whistler. He summered at Le Pouleu in southern Brittany with artists including Richard Emil Miller and Frederick Frieseke as well as at Etaples in Normandy.
Returning home, Dufner taught at the Buffalo Fine Arts Academy from 1903 to 1907. He then moved to New York and taught at the Art Students League. After leaving the league in 1917, he worked for several institutions, among them the Carnegie School of Technology in Pittsburgh and the Cooper Union in New York.
Dufner achieved a considerable reputation in Buffalo with paintings of a dark, monochromatic character that clearly demonstrated his affiliation with Whistler. After 1907, when he moved to the New York City suburb of Caldwell, New Jersey, his style changed radically. By 1911 he was painting out-of-doors and in a high-keyed palette and broken brushstroke, works that were to earn him the title "painter of sunshine." The artist attributed this stylistic change to his having seen an exhibition of work by Willard Metcalf.
Dufner had a long exhibition history with the Academy. He was first represented in an annual in 1904 and continued contributing works to the exhibitions into the 1940s.
