Incorporated as a District Municipality 10 November 1879, called The Corporation of Delta. "Delta (Municipal District)" adopted in the 18th Report of the Geographic Board of Canada, 31 March 1924, p.357; re-approved 11 February 1936. Reclassified as a city per Order in Council 362, 22 September 2017, to be known as the "City of Delta".
Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office
"So-called from the formation of the land by alluvial deposit from the Fraser River (Gosnell Year Book, 1897). The Fraser River delta extends, of course, far beyond the limits of the municipality, reaching the vicinity of Hope. River deltas are often triangular in shape, resembling the fourth letter of the Greek alphabet, delta, hence the name." [see also the municipality's own website.]
Source: Provincial Archives' Place Names File (the "Harvey File") compiled 1945-1950 by A.G. Harvey from various sources, with subsequent additions
"Ladner, February 14 - the Delta Council has declined to substitute numbers for the names of roads in the municipality as they obtain their appellation from pioneers of the district. The board of trade has requested the council to erect name signs at the crossings of the trunk and main roads." (Province newspaper, 15 February 1925.)