A cylindrical vibration isolating device having an inner cylinder, an outer cylinder surrounding the inner cylinder, an elastic leg having a pair of right and left leg portions to connect the inner cylinder and the outer cylinder and, when viewed in the axial direction of the inner cylinder, being formed in a substantially inverted V-shape while placing the inner cylinder in an intermediate position, and a mass projection being provided in the elastic leg such that the mass projection resonates in a frequency range that the elastic leg causes bending resonance. The mass projection is provided outside of an inner restraint line that is a perpendicular line passing an outermost point of an inner restrained portion that is a connected portion between the inner cylinder and the elastic leg.