| Honorific-Prefix: | The Hon. |
| James MacKerras Macdonnell | |
| Constituency Mp: | Muskoka—Ontario |
| Parliament: | Canadian |
| Predecessor: | Stephen Joseph Furniss |
| Successor: | The electoral district was abolished in 1947. |
| Term Start: | 1945 |
| Term End: | 1949 |
| Constituency Mp2: | Greenwood |
| Parliament2: | Canadian |
| Predecessor2: | John Ernest McMillin |
| Successor2: | Andrew Brewin |
| Term Start2: | 1949 |
| Term End2: | 1962 |
| Birth Date: | 15 December 1884 |
| Birth Place: | Kingston, Ontario |
| Party: | Progressive Conservative |
| Cabinet: | Minister Without Portfolio (1957-1959) |
James MacKerras Macdonnell, (December 15, 1884 - July 27, 1973) was a Canadian lawyer and parliamentarian.
He was born in Kingston, Ontario, the son of George W. Macdonnell and Mary Louise Philips, he was a Master at St. Andrew's College from 1904 to 1914 before becoming a trust company officer. He enlisted with the Canadian Expeditionary Force on September 24, 1914 at Valcartier, Quebec. He was awarded an MC in the 1917 Birthday Honours.[1]
Macdonnell was first elected to the House of Commons of Canada as a Progressive Conservative Party candidate in the 1945 federal election representing Muskoka—Ontario riding. He was defeated in the 1949 federal election, but returned to parliament later that year when he won a by-election held in the Toronto riding of Greenwood.
Following the 1957 federal election that returned the first Progressive Conservative government and the first Tory government since the Great Depression, the new Prime Minister of Canada, John Diefenbaker, named Macdonnell to Cabinet as a minister without portfolio. He resigned from Cabinet on August 8, 1959 for health reasons[2] and was defeated in the 1962 federal election by Andrew Brewin of the New Democratic Party.[3]
Macdonnell was appointed a Companion of the Order of Canada in 1967 for "services as a parliamentarian".