An optical element disposed between a light homogenizing element and a converging lens is provided. The optical element includes at least two regions. The at least two regions include a first region and a second region. The first region and the second region respectively adjust focus positions of a first beam formed through the first region and a second beam formed through the second region to substantially the same position. The first beam and the second beam have different wavelengths, and the first region and the second region meet at least one of the following conditions: the thicknesses of the first region and the second region are different; and the refractive indices of the first region and the second region are different. A projection apparatus including the optical element is also provided.