Grein may refer to:
People Alice Augusta Grein née Graveen (1874−1944), English actress, playwright and theatre producer, wife of Jakob Jakob Thomas Grein (1862–1935), Dutch theatre impresario and drama critic, husband of Alice Richard Frank Grein (1932−2024), American Episcopal clergyman
Places Grein, Austria, municipality in Perg, Upper Austria, Austria Grein Building, demolished building in Evansville, Indiana, United States of America Stadttheater Grein, theatre in Grein, Austria