To sufficiently correct lateral chromatic aberration by using a single optical element in a subsequent stage while aligning the directions of images in all fields of view, a wide-angle optical system (3) includes a first group (6) having negative and positive lenses (4 and 5), a second group (7) having a catadioptric optical element (14), and a third group (8). The catadioptric optical element (14) includes a first surface (11) at an object side, a second surface (12) at an image side, and a third surface (13). The first surface (11) has a first transmission surface (11a) and a first reflection surface (11b) disposed therearound. The second surface (12) has a second transmission surface (12a) and a second reflection surface (12b) disposed therearound. The third surface (13) is a circular conical transmission surface that is disposed between the first surface (11) and the second surface (12) and an apex of which is located at the object side. The expressions below are satisfied: ½n > ½p ± / 2 > 90 ° ˆ’ ¸k where vn denotes an Abbe number of the negative lens (4), vp denotes an Abbe number of the positive lens (5), ± denotes an apex angle of the third surface (13), and ¸k denotes a half field angle (0° < ¸k < 90°) of a principal ray at a minimum field angle within a lateral field of view.
