A stator for a rotary electric machine includes a stator core and a stator coil. The stator core includes plate groups circumferentially shifted from and stacked on one another. The stator core has slots. The stator coil includes segment conductors inserted in the slots respectively. The stator coil is assembled with the stator core. The plate groups each have, as grooves that form the slots, first grooves, and second grooves wider than the first grooves. At least one of the slots is configured with one or more of the first grooves and one or more of the second grooves.