Ascension Parish is a parish located in the U.S. state of Louisiana. As of the 2020 census, the population was 126,500. Its parish seat is Donaldsonville. The parish was created in 1807. Ascension Parish is part of the Baton Rouge metropolitan statistical area.

Donaldsonville is a city in, and the parish seat of Ascension Parish in the U.S. state of Louisiana. Located along the River Road of the west bank of the Mississippi River, it is a part of the Baton Rouge metropolitan statistical area. At the 2020 U.S. census, it had a population of 6,695.