Provided are an optical vibration-proof device, an optical device, and a fixing method of a magnetic sensor that can simply and accurately attach a magnetic sensor that detects a position of a lens for shake correction to a base member. An optical vibration-proof device includes a base member, a lens holding frame configured to be movable along a plane orthogonal to an optical axis with respect to the base member, a magnetic material that is moved integrally with the lens holding frame and generates a magnetic field, a position detection hall element (224) that detects a change in the magnetic field in accordance with movement of the lens holding frame, and a sensor attachment member (240) that is fixed to the base member, in which the base member includes a positioning part (134), the sensor attachment member (140) brings the position detection hall element (224) into contact with the positioning part (134) to position the position detection hall element (224), and the base member is formed integrally with the positioning part (134) as the same member, and is formed as a separate member from the sensor attachment member (240).