William Lockyer (1875 – 19 February 1959) was a British politician and trade unionist, who served on the London County Council.
Born in Lambeth, Lockyer came to prominence as the chair of the Postmen's Federation from 1904.
He supported the formation of a single union for post office staff, and chaired the conference which led the federation to merge with other unions, forming the Union of Post Office Workers.
Lockyer served as the union's treasurer until he retired in 1935.
At the 1937 London County Council election, he won a seat in Lambeth North, and he served until 1949.