Mary Margaret Beck Moser (October 12, 1924 – January 12, 2013) was an American field linguist and Bible translator who worked on behalf of the Seri people of Mexico for more than fifty years. She authored and co-authored numerous articles and two books (an ethnobotany and a substantive trilingual dictionary) about the language and culture of that group and brought to completion the translation of the New Testament in the Seri language.