A bearing device includes: a journal part, a main bearing, a cylinder block, and a bearing cap. One half bearing held by the cylinder block includes: a first circumferential oil groove and a second circumferential oil groove being formed at positions opposite to an inlet of an oil passage of the journal part; a separation part separating the first circumferential oil groove and the second circumferential oil groove; and a first oil hole and a second oil hole respectively penetrating from the first circumferential oil groove and the second circumferential oil groove to an outer circumferential surface. The cylinder block includes an oil distribution passage which is formed so as to extend across both the first oil hole and the second oil hole of the one half bearing.