Donauparkbahn, Narrow gauge railway in Donaupark, Vienna, Austria

Donauparkbahn is a narrow-gauge railway winding through Donaupark in Vienna, linking together different points of the park with three stations along its path. The track follows a figure-eight route that lets passengers travel through the scattered areas of this green space.

The Donauparkbahn was built for the Wiener Internationale Gartenschau 1964, the garden exhibition held in Donaupark, with a track gauge of 381 mm. Its first diesel locomotives arrived in 1963 (D2) and early 1964 (D1, D3), built by Rudolf Bauer, a firm with no locomotive-building experience. Until the late 1970s the depot and workshop stood on the opposite side of the park and had to give way to the construction of Uno-City; the present depot is on Arbeiterstrandbadstraße.

The three stations carry names tied to the park's history: Donauturm, Rosenschau, and Donau-City, called Haupteingang during the 1964 garden show and later Uno-City. One train, with locomotive D1, was painted by Austrian artists including Nina Biberle, Natascha Auenhammer, Karin Hannak and Yoly Maurer on the theme of peace; a carriage serves as an interactive guest book where riders write peace messages in paint pen.

The circuit runs counter-clockwise in a figure-eight shape with a maximum gradient of 28 per mille, and a full ride takes about 20 minutes. Tickets are sold by staff at the Donauturm and Rosenschau stations; boarding at Donau-City, the conductor directs passengers to buy at Donauturm. Two rebuilt trains have side-open cars with wheelchair compartments.

Steam locomotives never ran in regular service here; for the line's 50th anniversary, the Liliputbahn's Da 2 was brought by lorry and hauled passengers on three weekends from 30 August to 14 September 2014, at the age of 86.