A magnetic sensor includes a magnetic field conversion unit that outputs an output magnetic field, a magnetic field detection unit that the output magnetic field can be applied, and a magnetic shield that shields external magnetic fields. The length of the magnetic field conversion unit in the third direction is greater than the length in the second direction. The magnetic shield overlaps the magnetic field conversion unit and the magnetic field detection unit. The magnetic field detection unit includes a Wheatstone bridge circuit in which a first bridge circuit including first and second magnetic field detection units and a second bridge circuit including third and fourth magnetic field detection units are connected in parallel. The first through fourth magnetic field detection units include two magnetoresistive units, and two of the magnetoresistive units have magnetoresistive effect elements that include magnetization fixed layers whose magnetization directions differ from each other.