An optical measuring apparatus and method for a stereoscopic display device are capable of measuring optical characteristics of the stereoscopic display device. The optical measuring apparatus includes a test image supplier for generating a 3D test signal, a 3D display for displaying left-eye image and/or right-eye image based on the 3D test signal supplied from the test image supplier, an image selection member for selectively transmitting the left-eye image and right-eye image to be displayed on the 3D display, and a light measuring device that measures luminance of the image transmitted via the image selection member and calculates 3D image crosstalk of the left eye image and the right eye image based on the measured luminance.