There are provided a cubic boron nitride sintered body having a surface also excellent in adhesiveness to a ceramic coating film, while having excellent wear resistance and defect resistance, and a manufacturing method thereof, and a tool. The cubic boron nitride sintered body of the present invention includes 60.0 to 90.0% by volume of cubic boron nitride, the remainder being a binder phase, wherein the binder phase contains: at least any of a nitride, a boride, and an oxide of Al; at least any of a carbide, a nitride, a carbonitride, and a boride of Ti; and a compound represented by the following formula (1): W2NixCo(1-x)B2(0.40≤x