Phyllis Dewar (March 5, 1916 – April 8, 1961) was a Canadian freestyle swimmer who competed in the 1936 Summer Olympics.
She was born in Moose Jaw and died in Toronto.
In 1936 she was a member of the Canadian relay team which finished fourth in the 4 x 100 metre freestyle relay event. In the 100 metre freestyle competition she was eliminated in the semi-finals.
In the 1934 Empire Games she won the gold medal in the 100 yards contest, in the 440 yards freestyle event and in two relays. Four years later she won her fifth gold medal.
- 1930: 4×100 Yards Freestyle
- 1934–1966: 4×110 Yards Freestyle
- 1970–2010: 4×100 Metres Freestyle
- 1930: England (J. Cooper, D. Cooper, Joynes, Harding)
- 1934: Canada (Dewar, Humble, Hutton, Pirie)
- 1938: Canada (Oxenbury, Lyon, Baggaley, Dewar)
- 1950: Australia (Spencer, Norton, Davies, McQuade)
- 1954: South Africa (Loveday, Harrison, Petzer, Myburgh)
- 1958: Australia (Colquhoun, Fraser, Crapp, Morgan)
- 1962: Australia (Fraser, Bell, Thorn, Everuss)
- 1966: Canada (Tanner, Hughes, Kennedy, Lay)
- 1970: Australia (Cain, Langford, Watts, Watson)
- 1974: Canada (Jardin, Smith, Amundrud, Wright)
- 1978: Canada (Klimpel, Amundrud, Sloan, Quirk)
- 1982: England (Gore, Willmott, Croft, Fibbens)
- 1986: Canada (Nugent, Kerr, Rai, Noall)
- 1990: Australia (Mullens, Wirdum, Curry-Kenny, O'Neill)
- 1994: Australia (Windsor, Lewis, Stevenson, O'Neill)
- 1998: Australia (Rooney, Denman, Thomas, O'Neill)
- 2002: Australia (Mills, Henry, Thomas, Ryan)
- 2006: Australia (Lenton, Barratt, Stubbins, Mackenzie)
- 2010: Australia (Coutts, Guehrer, Galvez, Seebohm)
- 2014: Australia (B. Campbell, Schlanger, McKeon, C. Campbell)