| John Ritchie MacNicol | |
| Parliament1: | Canadian |
| Constituency Mp1: | Davenport |
| Term Start1: | 1935 |
| Term End1: | 1949 |
| Predecessor1: | New riding |
| Successor1: | Paul Hellyer |
| Parliament2: | Canadian |
| Constituency Mp2: | Toronto Northwest |
| Term Start2: | 1930 |
| Term End2: | 1935 |
| Predecessor2: | Thomas Langton Church |
| Successor2: | Riding abolished |
| Party: | Conservative |
| Birth Date: | 31 August 1878 |
| Birth Place: | Beaverton, Ontario, Canada |
| Profession: | School teacher |
John Ritchie MacNicol (August 31, 1878 - June 18, 1950) was a Canadian politician.
Born in Beaverton, Ontario, MacNicol was educated at public school, collegiates, and at Bryant & Stratton College in Buffalo, New York. He taught school in Algoma and Grey Counties, Ontario. From 1917 to 1920, he was president of the South York Liberal-Conservative Association. From 1921 to 1922, he was president of the Ward 6 Toronto Association. From 1921 to 1923, he was secretary of the Liberal-Conservative Association of Ontario and was president from 1923 to 1930. He was president of the federal Conservative Party from 1925 to 1943.
He was first elected to the House of Commons of Canada for the Ontario riding of Toronto Northwest in the 1930 federal election. He was re-elected in 1935, 1940, and 1945 for the riding of Davenport. He was defeated by Paul Hellyer in the 1949 election.