From 2011 to 2018 he was head of the FPÖ Youth Ring, from 2010 to 2018 Landbauer was a municipal politician in Wiener Neustadt and from 2013 to 2018 he was a member of the provincial parliament (Landtag) of Lower Austria.

As a result of the affair surrounding the Germania zu Wiener Neustadt fraternity, he resigned from all political functions on 1 February 2018 and suspended his FPÖ party membership.

Landbauer joined the Lower Austrian Ring Freiheitlicher Jugend (RFJ) at the age of 14, and became a member of its regional board in 2003.

[10] In 2010 Landbauer supported the organisation "Junge Patrioten - Verein zur Erziehung zu politischer Verantwortung", an extreme right-wing group with "folk-fundamentalist orientation".

From 2011 to 2014 he worked in the "Klub der Wiener Freiheitlichen Landtagsabgeordneten und Gemeinderäte" as a political adviser to the Klubobmannes.