Provided are a cBN sintered body having excellent wear resistance and a small specific resistance, and a cutting tool that uses the cBN sintered body and has excellent machinability and excellent wear resistance. The cBN sintered body contains cBN particles whose proportion is 85-97% by volume, and a binding phase whose proportion is 3-15% by volume. The cBN sintered body contains Al whose ratio to the entirety of the cBN sintered body is 0.1-5% by mass, and Co whose mass ratio to the Al is 3 to 40, and includes Al 3 B 6 Co 20 . The cutting tool, such as a cutting insert 1, uses the cBN sintered body as a cutting edge part 5.