William Neilson (Manitoba politician)
 William Johnston Neilson (March 4 1854 – July 17 1903) was a physician and political figure in Manitoba. He represented Winnipeg North from 1900 to 1903 in the Legislative Assembly of Manitoba as a Conservative.He was born in Perth Lanark County Canada West and was educated at McGill College where he studied medicine. In 1881 Nielson moved to Winnipeg and lectured on anatomy at the Manitoba Medical School.