Edwin Costley Jellett (November 22, 1860 – March 8, 1929) was an American engineer, botanist, gardener, photographer, artist, and diarist who wrote books and articles about Germantown, Philadelphia, Pennsylvania and its flora. His writing covers Germantown's historic homes, natural environment, gardens, and prominent residents. He was active in the Germantown Horticultural Society and in the Germantown Historical Society. A collection of his papers is held by the University of Pennsylvania and Historical Society of Pennsylvania. Jewett wrote a series of weekly articles titled A Flora of Germantown that was published in Germantown's newspaper every Friday for almost 40 weeks in 1903 and covered plants, flowers, and local history noted from his wanderings in Northwest Philadelphia (Germanto