Geismar is an unincorporated community in Ascension Parish, Louisiana, United States and is at the heart of Louisiana's chemical corridor. The community is part of the Baton Rouge metropolitan statistical area. Geismar is south of Prairieville and west of Gonzales. The community has two schools, Dutchtown Primary/ Middle School and Dutchtown High School, which are ranked among the top schools in the state of Louisiana. The Mississippi River flows to the southeast along the southwest side of the community. The area is vulnerable to hurricanes and tropical systems due to its low elevation and its proximity to the coast of southeast Louisiana.