There is a project called GeoPolars: https://github.com/geopolars/geopolars

From the README:

> Update (August 2024): GeoPolars is blocked on Polars supporting Arrow extension types, which would allow GeoPolars to persist geometry type information and coordinate reference system (CRS) metadata. It's not feasible to create a geopolars. GeoDataFrame as a subclass of a polars. DataFrame (similar to how the geopandas. GeoDataFrame is a subclass of pandas.DataFrame) because polars explicitly does not support subclassing of core data types.

I'm working on implementing extension types in Polars. Stay tuned.