Bo District is a district in the Southern Province of Sierra Leone. It is the second most populous District in Sierra Leone (after the Western Area Urban District). Its capital and largest city is the city of Bo, which is the second largest city in Sierra Leone. other major towns in the district include Baoma, Bumpeh, Serabu, Sumbuya, Baiima and Yele. The district population as of 2010 is 561,524. Bo District is subdivided into fifteen chiefdoms.