Fladnitz im Raabtal is a former municipality in the district of Südoststeiermark, in the Austrian state of Styria. It lies in the Raab valley, from which it takes the second part of its name.
Since the 2015 Styria municipal structural reform, Fladnitz im Raabtal is no longer an independent municipality and is now part of the municipality of Kirchberg an der Raab.