Margaret Ellis Millar (née Sturm) was an American-Canadian mystery and suspense writer. Born in Kitchener, Ontario, she was educated there and in Toronto. She moved to the United States after marrying Kenneth Millar (better known under the pen name Ross Macdonald). They resided for decades in the city of Santa Barbara, which was often utilized as a locale in her later novels under the pseudonyms of San Felice or Santa Felicia.