Gustav Jahn (17 May 1879, Vienna - 17 August 1919, on the Großer Ödstein [de], Ennstal Alps) was a landscape painter, poster artist and mountaineer who lived most of his life in the Austro-Hungarian Empire.

Then in 1896, at age 16, he was admitted to the Academy of Fine Arts, Vienna, studying with August Eisenmenger and Alois Delug.

As part of the Rome Prize, he won a Kenyon study scholarship in 1904, which he used more for climbing in the Mont Blanc area than painting.

[3] Starting in 1898 as a student, he furnished the illustrations for the catalogs of "Bergsporthaus", a store selling mountaineering equipment owned by ski racer Mizzi Langer-Kauba [de], which was the first of its kind in Vienna.

While his sheets still had the effect of paintings and were not really flat and "poster like", their design was intended for indoor advertising at stations, for which the decorative character was in the foreground.

[6] These achievements led to his serving as an instruction officer during World War I teaching mountain warfare in the Dolomites, a time during which he also painted on the side.