A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a rear lens group including one or more lens units. The distance between adjacent lens units changes during zooming. The first lens unit is closer to the object side at a telephoto end than at the wide-angle end. The second lens unit includes a first negative lens, a second negative lens, and a third negative lens in this order from the object side. The focal lengths of the zoom lens at the wide-angle end and at the telephoto end, the focal length of the first lens unit, and the focal length of the second lens unit are appropriately set based on predetermined mathematical conditions.