Edith Margaret Bell Douglas (February 7, 1880 – October 10, 1963) was a Canadian botanist and horticulturist known for her work in the Southwestern United States and Mexico.
She helped establish the Desert Botanical Garden and donated 1,500 of her own specimens to its herbarium.
She is a member of the Arizona Women's Hall of Fame and the namesake of the Garden Club of America's Margaret Douglas Medal.