A magnetic position detector (2) includes a rotary mag­netic recording medium, which is divided into plural channels (CH0, CHl, CH2, CH3) each consisting of two tracks. A magnetic sensor (8) is fixedly provided so that, for each channel, two sets of magnetoresistive elements (R) spaced by a predetermined distance face the tracks, each set being composed of two elements. First elements of both the sets facing one of the tracks and second elements thereof facing the other track are structurally coupled at respective adjacent ends. Two coupling points thereof are connected to terminals for deriving output voltages from the elements and remaining ends opposite to the coupled ends to terminals for supplying the elements with source voltage. The second elements corresponding to a channel are structurally coupled with the first elements corresponding to an adjacent channel, wherein coupling points are connected to the terminals for supplying the source voltage.
According to this, the sensor (8) can be made small in size and the resistivity against noise is much enhanced.