Walter Mittelholzer (born April 2, 1894 in St. Gallen; died May 9, 1937 in Styria) was a Swiss aviation pioneer. He was active as a pilot, photographer, travel writer, and also as one of the first people to fly a plane.

Mittelholzer got his private pilot's license in 1917, and in 1918 he completed his instruction as a military pilot.

On November 5, 1919 he founded an air-photo and passenger flight business, Comte, Mittelholzer, and Co. In 1920 he merged this firm with the financially stronger Ad Astra Aero. Mittelholzer was the director and head pilot of Ad Astra Aero.

He made the first North-South flight across Africa. It took him 77 days. He started in Zurich on December 7, 1926, flying via Alexandria and landing in Cape Town on February 21, 1927. On December 15, 1929 he became the first person to fly over Mt. Kilimanjaro. In 1931 he became the technical director of a new airline called Swissair. He died in 1937 in an accident on a transmountain flight over Styria.