A plurality of imaging optical systems includes at least two imaging optical systems, and each imaging optical system includes an identical diaphragm member. Each imaging optical system includes in order from an object side, a front lens unit having a positive refractive power, a focusing lens unit having a negative refractive power, and a rear lens unit having a positive refractive power. The diaphragm member is disposed near the focusing lens unit. At the time of focusing, only the focusing lens unit moves on an optical axis. Each imaging optical system satisfies the following conditional expression (1), and the plurality of imaging optical systems satisfies the following conditional expressions (2) and (3). 0.5