To provide a workpiece positioning device capable of easily arranging a workpiece at a suitable position despite of variation in workpiece dimensions.

The workpiece positioning device includes: a horizontal cam member 20 for advancingly/retreatingly supporting a second gage 3a to a first gage 2a and a vertical cam member 4 for pressing the horizontal cam member in a horizontal direction by descending movement of an upper mold and moving the second gage to a first gage side. A first elastic member 27 extendable/shrinkable along the advancing/retreating direction of the second gage is interposed between the horizontal cam member and the second gage. The workpiece W is carried in between the first gage and the second gage. The second gage presses the end of the workpiece while the upper mold is descendingly moved, the workpiece is sandwiched by the first gage and the second gage, difference between the movement amount of the horizontal cam member and the movement amount of the second gage is absorbed by the first elastic member.