Mary Townsend may refer to:

• Mary Townsend (entomologist) (1814–1851), American abolitionist and entomologist
• Mary Townsend (artist) (1822–1869), New Zealand artist
• Mary Ashley Townsend (1836–1901), American poet
• Mary Elizabeth Townsend (1841–1918), British philanthropist and co-founder of the "Girls' Friendly Society"
• Mary Townsend Seymour (1876–1957), African-American politician