A cutting insert includes a rake face, a flank face, and a cutting edge constituted of a ridgeline between the rake face and the flank face. The cutting edge has a first cutting edge portion for corner processing, a second cutting edge portion for low cut-in pulling processing, a third cutting edge portion for high cut-in pulling processing, a fourth cutting edge portion for finished-surface processing, a first connection cutting edge portion, a second connection cutting edge portion, and a third connection cutting edge portion. The fourth cutting edge portion is disposed between the first cutting edge portion and the second cutting edge portion. The second cutting edge portion is disposed between the fourth cutting edge portion and the third cutting edge portion. Each of the first cutting edge portion, the second cutting edge portion, and the fourth cutting edge portion has a curved shape.