A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a rear unit including at least one lens unit. In the zoom lens, the locus of movement, the focal length, the amount of displacement during zooming, and the shapes of lens surfaces are appropriately set for each lens unit.