The village Grundlsee is situated at an elevation of 712 m on the lake Grundlsee, the largest lake (5.7 km long, up to 0.9 km wide, 64 m deep) of Styria. It developed at an old trading path that was used for bringing salt from Altaussee southward to the Enns river valley. The first mention in a document dates back to 1295 (de lacu chrungelse).
The parish church Herz Jesu (Heart of Jesus) [centre] was erected in 1888–1890 in Neo-Gothic style.
Grundlsee became an independent parish in 1952; before that it was part of the parish Bad Aussee.