- Louisa is a city located in Lawrence County, Kentucky, United States. It is the county seat of Lawrence County and has a population of approximately 2,474 people. The city is situated along the Big Sandy River and is known for its rich history and natural beauty. Louisa offers various recreational activities, including fishing, hiking, and boating, making it a popular destination for outdoor enthusiasts. It also has a number of historical landmarks, such as the Dawkins Line Rail Trail and the Yatesville Lake State Park. Overall, Louisa is a small but charming city with a close-knit community and picturesque surroundings.