- Mobile is a city located in the state of Alabama, United States. It is the county seat of Mobile County and is situated on the Gulf Coast, along the Mobile River. Mobile is the third most populous city in Alabama, with an estimated population of around 189,572 as of 2021. The city has a rich history and is known for its cultural diversity, Mardi Gras celebrations, and historic architecture. Mobile is also an important port city, with a bustling waterfront area and a significant shipping industry.