A photoelectric conversion apparatus includes a photoelectric conversion element including a pixel area where a plurality of pixels composed of avalanche photodiodes for photoelectrically converting an optical image is two-dimensionally arranged, the photoelectric conversion element being configured to simultaneously read signals from a first pixel group and a second pixel group in the pixel area, at least one processor, and a memory coupled to the at least one processor, the memory storing instructions that, when executed by the at least one processor, cause the at least one processor to generate an image based on the read signals, acquire characteristic information regarding crosstalk between the plurality of pixels, generate correction information based on the characteristic information, and perform a correction process on the image using the correction information. Correction information different between the first and second pixel groups is generated.