Part of Allen Parish, west of the Calcasieu River, lies within the historical "No Man's Land" or Neutral Ground of disputed territory between the US and Spain.

The Calcasieu river forms the primary boundary between the piney woods and prairie regions of the parish.

As of the 2020 United States census, there were 22,750 people, 7,925 households, and 5,566 families residing in the parish.

[18] The Coushatta Tribe of Louisiana's territory is bounded within Allen and Jefferson Davis parishes, and the tribe maintains traditional creative expressions such as music, dance, and fiber arts.

An annual powwow celebrating these arts takes place at the Coushatta Casino Resort near Kinder.

[20] On September 27, 2008, the Allen Parish Tourist Commission opened Leatherwood Museum in Oakdale in a two-story house which served during the early 20th century as a hospital where women waited on the second-floor balcony to deliver their babies.

Allen is part of Louisiana's 4th congressional district, held by Republican Mike Johnson.

In the Louisiana House of Representatives Allen is part of the 32nd district, held by Republican R. DeWitt Carrier.

In the Louisiana Senate Allen is part of the 28th district, held by Republican Heather Cloud.

[25] Allen Parish's newspapers are The Oakdale Journal and The Kinder Courier News, owned by Louisiana State Newspapers, Inc.[26][27] Allen Parish is home to one FM radio station, KKST-FM, an urban contemporary station in Oakdale.

[30] Kinder and Oberlin primarily receive Lake Charles station KPLC (NBC and CW).

The nearest long-distance bus stations are in Alexandria, Opelousas, Lafayette, and Lake Charles.

Detachment 1, B Company 3-156TH Infantry Battalion of the 256TH IBCT resided in Oakdale, Louisiana.