We report on iodine doping of molecular beam epitaxy (MBE)-grown Cd(Mn)Te quasi-bulk films and modulation-doped CdTe/Cd1−yMgyTe two-dimensional (2D) single quantum well structures. Modulation doping with iodine of CdTe/Cd1−yMgyTe structures resulted in fabrication of a 2D electron gas with mobility exceeding 105 cm2/(V s). This is the highest mobility reported in wide-gap II-VI materials