Map - Sinoe County (Sinoe County)

Sinoe is one of Liberia's 15 counties and it has 17 districts. Greenville is the county's capital. As of the 2008 Census, it had a population of 104,932, making it one of the least populous counties in Liberia. Sinoe has the third-largest area of all Liberia's counties; it has the second least-dense population after Gbarpolu County. The County was originally a colony in the name Mississippi-in-Africa, under auspices of a chapter of the American Colonization Society as it was created with slaves from Mississippi to Liberia.

There are seventeen districts in the county and it has lower tropical forests which has mid size hills composed of various valleys and water courses. Sapo National Park (180436 ha, a National protected area, Sankwehn Proposed Reserve, occupying an area of 80348 ha, a National proposed reserve and LTPC Reforestation Project with an area of 154.2 ha are the major plantation areas in the county.

The flag is a green cross on a white background with the flag of Liberia in the top-left corner.

Long settled by indigenous peoples, this area became colonized by more than 300 freed African-American slaves from Prospect Hill Plantation, Mississippi in 1835. The colony was originally called Mississippi-in-Africa, under auspices of a chapter of the American Colonization Society. Greenville was named after Judge James Green and was established with the freed Black Americans of the society in 1838. Green was instrumental in bringing a group of slaves from the Mississippi Delta to Liberia. The town was a prominent exporter of rubber, lumber and agricultural products. It was destroyed during the First Liberian Civil War but has been rebuilt. There is boat connectivity from the town to Monrovia and Harper.