The 66th Light Anti-Aircraft Regiment, RCA originated in Nanaimo, British Columbia on 1 August 1930, when the 2nd Battalion, The Canadian Scottish Regiment was authorized to be formed. On 15 December 1936, it was amalgamated with A Company, 11th Machine Gun Battalion, CMGC, and redesignated the 2nd Battalion (Machine Gun), The Canadian Scottish Regiment. On 1 April 1946, it was converted to artillery and redesignated the 66th Light Anti-Aircraft Regiment (Canadian Scottish Regiment), RCA. On 31 December 1954, it was amalgamated with The Canadian Scottish Regiment (Princess Mary's) and the 62nd Anti-Tank Battery, RCA.