- Sir William Vaughan
- Sir William Wilfred Sullivan
- Sir William Young
- Sir Willoughby Garnons Gwatkin
- Sirmilik National Park
- Sister Gilberte Villeneuve
- Sister Marguerite Jean, S.C.I.M.
- Sister Marie-Stéphane
- Sisters of Providence
- Sisters of St Anne
- Sisters of St Joseph
- Sisters of the Holy Names of Jesus and Mary
- Sitting Bull
- Six Brown Brothers
- Six Nations of the Grand River
