Gloggnitz is a mountain town in the Neunkirchen district of Lower Austria, Austria.

Gloggnitz is situated in the south-western part of the Vienna Basin in Lower Austria. It is surrounded by the highest mountains in Lower Austria, Mount Rax (2007m / 6585 ft) and Mount Schneeberg (2076m / 6811 ft). The town is also a major traffic junction: Gloggnitz is situated on the main Südbahn (the important rail route between Vienna and Trieste in Italy) and the S6 motorway.

Gloggnitz is famous for producing two of Austria's most distinguished Federal Presidents. Federal President Dr Michael Hainisch (1858–1940) and the Chancellor of State and later Federal President Dr Karl Renner (1870–1950) were both Gloggnitz citizens. Dr Karl Renner spent 42 years of his life in Gloggnitz (up until his death in 1950). On the occasion of the anniversary of his hundredth birthday a monument was erected in Dr Karl Renner Square. A museum in his former residence also commemorates the life of this highly respected former Gloggnitz resident.