Abstract: We present a theoretical investigation of the molecular-frame photoelectron angular distribution (MF-PAD) resulting from the inner-shell photoionization of fixed-in-space CO molecules with elliptically polarized light. The MSXα output program, originally written for linearly polarized light, was changed in order to calculate the MF-PAD for circularly and elliptically polarized light. The calculations were made for CO C(1s) inner-shell photoionization for 3, 10, and 30 eV kinetic energy electrons. The MF-PADs were calculated from 0° angle of ellipticity (equivalent to linear polarized light parallel to the molecular axis) in steps of 5° (corresponding to different types of elliptical light) up to 90° (equivalent to linear polarized light perpendicular to the molecular axis). Graphical abstract: [Figure not available: see fulltext.].