Ernest Ačkun (Ернест Ачкун) (March 27, 1930 – September 28, 2001) was a Yugoslav clarinetist.

Ačkun gave concerts as a soloist in nearly all great towns in Yugoslavia, as well as in France, West Germany, Austria, Italy and Bulgaria, playing under the leadership of such conductors as Zubin Mehta, Jean Martinon, Charles Bruck, Krešimir Baranović, Oskar Danon, Milan Horvat, Živojin Zdravković.

Distinguished Yugoslav composers, such as Stjepan Šulek and Zlatan Vauda, dedicated their compositions to him.

He was also rewarded the UMUS award for the best music performance achievement in the previous concert season (1984).

In 1992 he was a jury member on the ARD International Music Competition in Munich, along with Eugene Rousseau (United States), Eduard Brunner (Switzerland), Philippe Cuper (France), Giora Feidman (Argentina), Lutz Kŏhler (Germany), Lew Mikhailow (U.S.S.R.), Charles Neidich (U.S.A.) and Ulf Rodenhäuser (Germany).