Edgar Charlotte Rossie was born on September 6, 1875 in London, Ontario to William C. and Lucy Jane (Westlake) Rossie. He received his early education in London and at Pickering College in Oshawa. As a youth, Rossie was employed at the photographic studio of his uncle, Frank Westlake, and was apprenticing under Westlake by 1895. In 1899, Rossie located to Winnipeg, Manitoba and established himself locally as a prominent photographer. He was commissioned by the Royal North-West Mounted Police for a photographic project in Regina, North-West Territories in 1904. Soon after completing his work, he chose to relocate to Regina and by late 1904 had established a photographic studio in the city.
Rossie's photographic works ranged from portraiture of local families to scenes documenting the economic, political, social and cultural life of Regina, especially in its years of rapid growth during the first two decades of the twentieth century. His portraiture of politicians, First Nations leaders and royalty gained him critical acclaim and recognition throughout North America and western Europe. Rossie's works were exhibited in galleries in the United States, France and England throughout the 1920s and 1930s. Additionally, he was a local pioneer in the use of panoramic photography in the 1910s and 1920s, and is reported to have been the first person to create moving picture films in Saskatchewan.
In addition to his photographic studio, Rossie owned a photo finishing and supply company. Rex Photo Supply Co. Ltd. was incorporated in 1930 and continued operation until 1943.
Rossie was active in the community as a member of the N.W.M.P. Lodge No. 11, A.F. & A.M., the Wascana Preceptory Knights Templar, the Wa Wa Temple and local baseball and hockey organizations. He was also instrumental in the development of the resort community of Regina Beach in the 1910s.
Edgar Rossie died in Regina on March 13, 1942. He was buried near Regina Beach.