An optical member includes aperture regions, a lens device, and an imaging apparatus. A lens device includes: an imaging optical system; a first polarizing part that polarizes at least a part of rays transmitted through the imaging optical system; and a filter unit that is disposed at a pupil position of the imaging optical system or near the pupil position, and includes aperture regions transmitting the rays of the imaging optical system and including a first aperture region and a second aperture region, wavelength selective filters disposed in the first aperture region and the second aperture region and transmitting pieces of light of which at least a part of wavelength ranges are different from each other, and a second polarizing filter including polarizing filters disposed in the first aperture region and the second aperture region and having polarization directions different from each other.