Saint Mary's Township (also designated Township 16) is one of twenty townships within Wake County, North Carolina. As of the 2000 census, Saint Mary's Township had a population of 38,272, a 18.6% increase over 1990, and a population density of 1.06 people per acre (262/km²).

Saint Mary's Township, occupying 36,032 acres (146 km²) in southeastern Wake County, includes most of the town of Garner and portions of the city of Raleigh.