Elizabeth Gertrude Britton (née Elizabeth Gertrude Knight) (January 9, 1858 – February 25, 1934) was an American botanist, bryologist, and educator. She and her husband, Nathaniel Lord Britton played a significant role in the fundraising and creation of the New York Botanical Garden. She was a co-founder of the predecessor to the American Bryological and Lichenological Society. She was an activist for protection of wildflowers, inspiring local chapter activities and the passage of legislation. Elizabeth Britton made major contributions to the literature of mosses, publishing 170 papers in that field.