Francis Evans Cornish (February 1, 1831 – November 28, 1878) was a politician in the Canadian provinces of Ontario and Manitoba. He served as Mayor of London, Ontario, in the early 1860s, became the first Mayor of Winnipeg in 1874, and was for a time a member of the Manitoba legislature.

Cornish was born in London, Ontario, to a family that had moved to Canada from England twelve years earlier. He was educated in London, articled in law, and was called to the bar of Upper Canada in 1855. At age 26, he was appointed a Q.C. He was a successful lawyer, and was involved in the local masonic and Orange lodges.

London was incorporated as a city in 1855, and Cornish was elected as an alderman in its seventh ward three years later. He was re-elected in 1859 and 1860. In May 1860, Cornish ran as a Conservative for the riding of Middlesex East in a by-election for the Province of Canada's legislature. He was defeated by R. Craik , a Liberal. There was a second Conservative candidate in the race, and some suspect that Cornish deliberately split the Conservative vote to permit Craik's victory.

Cornish was elected Mayor of London in 1861, and held the position for the next four years. Cornish was responsible for resolving a scandal at the city's hospital, and oversaw the city's first serious efforts to reduce fire hazards in the its central region. The most notorious incident of his tenure as Mayor occurred in 1863, when he physically attacked a British commander who boasted of having an affair with Cornish's wife. He was convicted of assault, and fined eight dollars.

Cornish often resorted to dubious means to win elections, and received assistance to this end from members of the local Orange Order. He was defeated for the mayoralty in 1865, when his opponent David Glass successfully petitioned for the local militia to oversee the proceedings.

Cornish ran for the Ontario legislature in 1871, but was defeated by John Carling, local brewer and fellow Conservative, by 985 votes to 558. Cornish's loyalty to the Conservative Party was somewhat ambiguous in this period; some sources suggest that he was a Liberal by this time, but this is at best uncertain.

Although he had been re-elected to London's municipal council in 1871, Cornish had little continued interest in the city. He moved to Winnipeg in 1872, and helped in the development of the new province's legal system. He became a spokesman for recent Ontario immigrants, and forged an alliance with John Christian Schultz's Canadian Party, which opposed the province's governing alliance and was often involved in violent activities against the local Métis population.

Against the wishes of Prime Minister John A. Macdonald, Cornish was responsible for coordinating the arrest of Ambroise Lepine , adjutant-general in the provisional government of Louis Riel, in late 1873. The following year, he was the leader of the prosecution in Lepine's trial, which resulted in a conviction and a death sentence (later reduced to a minor jail sentence).

Winnipeg was formally incorporated as a city in 1873, and Cornish declared himself a candidate for the city's mayoralty soon thereafter. On January 5, 1874, he defeated Liberal William F. Luxton by 383 votes to 179. It may be noted that there were only 382 eligible voters in the city at the time, although property owners were allowed to vote in every riding in which they owned property.

Later in 1874, Cornish declared himself a candidate for the Manitoba legislature in the rural riding of Poplar Point . Running in opposition to the government of Robert A. Davis (which was backed primarily by francophones), he defeated his sole opponent Robert Hastie by 92 votes to 65. He subsequently allowed his name to stand for re-election as mayor of Winnipeg, but paid little attention to the campaign and was defeated by William Kennedy, 218 votes to 164.

Early in 1875, opposition leader John Norquay entered the cabinet of Premier Davis and brought several anglophone supporters with him to the government side. Cornish did not join Norquay, and eventually emerged as the leader of the parliamentary opposition. He was again accused of fomenting violence in a municipal election in 1876, and was fined twenty dollars for his role in an altercation.

Cornish was asked to run as a Liberal in the federal election of 1878, but declined. His party affiliation was still ambiguous in this period; he declared himself a "National" in federal politics, and is generally considered to have been a Conservative, albeit of an independent stripe, during his time in the Manitoba legislature.

Cornish returned to the municipal council of Winnipeg in 1878 as an alderman. He was also planning to run for re-election to the provincial legislature, but died of cancer of the stomach in November.