Mattie Edwards Hewitt was an American photographer of architecture, landscape, and design, primarily based on the East Coast. Initially she was associated with Frances Benjamin Johnston, who later became her lover, living and working with her for eight years from 1909. Together they established the Johnston-Hewitt Studio in New York City, which functioned from 1913 till 1917. They became well known in the field of architectural and landscape photography and took many pictures of famous buildings and gardens, which were titled "Miss Johnston and Mrs. Hewitt" or "Frances Benjamin Johnston and Mattie Edwards Hewitt."
After the partnership with Johnston broke up in 1917, Hewitt began to work solo and became famous in her own right as a commercial photographer. She set up her business in photography with a specific focus on taking pictures for designers, architects, and landscape architects, recording interior and exterior views of home and business houses, and gardens. She continued in the profession until her death in Boston in 1956.