Koidu is one of the most ethnically and religiously diverse cities in Sierra Leone. The city is inhabited by significant numbers of many of Sierra Leone's ethnic groups, with no single ethnic group forming a majority. The Krio language is by far the most widely spoken language in Koidu Town and is the primary language of communication in the city. Koidu Town is the hometown of Sierra Leone's vice president Mohamed Juldeh Jalloh, Sierra Leone"s First Lady Fatima Bio and former Sierra Leone"s vice president Samuel Sam-Sumana; as all three of them were born and raised in the city.