McAlester is a city in Pittsburg County, Oklahoma, United States. It is the county seat of Pittsburg County and is located in the southeastern part of the state. The city has a population of approximately 18, cultural attractions, and a variety of recreational opportunities. It is known for its historic downtown area, which features numerous shops, restaurants, and buildings dating back to the late 1800s. The city is also home to the Oklahoma State Penitentiary, the oldest continually operating prison in the state.