[3] The parish is named for René-Robert Cavelier, Sieur de La Salle.

There is some confusion as to whether the parish is spelled "LaSalle" (no space) or "La Salle."

An example of the latter view can be seen in the photo at right of the sign over the entrance to a "La Salle Parish Courthouse."

[8] As of the 2020 United States census, there were 14,791 people, 4,814 households, and 3,643 families residing in the parish.

LaSalle Parish has been staunchly Republican since 1956, except in 1968 when it voted strongly for American Independent nominee George Wallace.

Prior to that, it had been heavily Democratic, but no Democratic nominee since 1956 besides Jimmy Carter has passed forty percent of the parish’s vote, with Hillary Clinton, Joe Biden, and Kamala Harris not even reaching double digits.