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, one or two intermediate lens units having positive refractive powers, and a final lens unit having a positive power. A distance between each pair of adjacent lens units changes in zooming from a wide-angle end to a telephoto end. The one or two intermediate lens units include three or four lenses. The one or two intermediate lens units include a single lens having a positive refractive power and being closest to the image side. The final lens unit includes three or four lenses. The zoom lens satisfies specified conditional expressions.