An imaging lens assembly includes a plastic barrel and a lens set, and the lens set is disposed in the plastic barrel. The plastic barrel includes an object-side outer surface, a first inner surface and a second inner surface. The lens set has an optical axis, and includes, in order from an object side to an image side thereof, at least one plastic lens element and a spacer. A light-absorbing coating is disposed on the plastic lens element. The spacer includes an object-side connecting surface and a relative surface. When the object-side connecting surface is connected with a neighboring object-side optical element, the relative surface is out of touch with the neighboring object-side optical element. There is an overlap between the second inner surface and the relative surface along a direction parallel to the optical axis.