| Thomas Mayne Daly | |
| Office1: | Ontario MPP |
| Term Start1: | February 1, 1874 |
| Term End1: | December 23, 1874 |
| Predecessor1: | Andrew Monteith |
| Successor1: | David Davidson Hay |
| Constituency1: | Perth North |
| Riding2: | Perth North |
| Parliament2: | Canadian |
| Term Start2: | 1872 |
| Term End2: | 1874 |
| Predecessor2: | James Redford |
| Successor2: | Andrew Monteith |
| Office3: | Legislative Assembly of the Province of Canada |
| Term Start3: | 1862 |
| Term End3: | 1863 |
| Predecessor3: | Michael Hamilton Foley |
| Successor3: | Robert MacFarlane |
| Term Start4: | 1854 |
| Term End4: | 1861 |
| Predecessor4: | New riding |
| Successor4: | Michael Hamilton Foley |
| Constituency4: | Perth County, Province of Canada |
| Party: | Conservative |
| Birth Date: | 17 February 1827 |
| Birth Place: | Hamilton, Upper Canada |
| Death Place: | Stratford, Ontario, Canada |
| Profession: | Businessman |
Thomas Mayne Daly (February 17, 1827 – March 4, 1885) was a businessman and political figure in Canada West (later Ontario). He represented the riding of Perth North in the House of Commons of Canada and Perth North in the Ontario Provincial Parliament.
He was born in Hamilton, Upper Canada in 1827 and studied at Upper Canada College. He ran a stage coach company, operated a grain mill and published the Stratford Examiner. He was a contractor, building roads in Perth County and also railroads in Canada and the United States. From 1848 to 1849, he served on the Huron District council and, in 1850, on the council for the united counties of Huron, Perth and Bruce.
In 1854, he was elected to the 5th Parliament of the Province of Canada representing Perth County; he originally described himself as an independent Reformer, but tended to support the Liberal-Conservative party once elected. He was reelected in 1857 but was defeated by Michael Hamilton Foley in 1861. Foley was appointed to the cabinet and ran in Waterloo North; Daly defeated Robert MacFarlane in an 1862 by-election to regain the seat for Perth. However, in 1863, McFarlane won the seat.
Daly was mayor of Stratford from 1869 to 1870 and again from 1876 to 1878. In 1872, he was elected to the House of Commons for Perth North. He was elected for Perth North provincially in an 1874 by-election, but was not reelected in 1875. In 1884, he was appointed deputy collector of customs at Stratford, thanks to his connections with the Conservative Party. He died in Stratford in 1885.
His son, Thomas Mayne Daly, was a member of parliament and cabinet minister from Manitoba.