Sir James David Edgar (August 10, 1841 - July 31, 1899) was a Canadian politician.

In his twenties Edgar was a law student, legal editor of the Toronto Globe, an alderman on Toronto's city council and an organizer for the Liberal Party in Ontario. He was also rare among English Canadians of the time for his sympathy for the rights of French-Canadians.

Born in the Eastern Townships of Canada East (later Quebec), Edgar was educated in Lennoxville and Quebec City before moving to Toronto as an adult where he became a lawyer. He was elected an Alderman in 1866 and was a supporter of George Brown and the Reform Party. He ran as a Liberal in the 1871 Ontario election but was defeated by a margin of four votes in his attempt to win a seat in the provincial legislature. He was first elected to the Canadian House of Commons in the 1872 Canadian election and became Whip in the caucus of Alexander Mackenzie and helped bring down the Conservative government over the Pacific Scandal. However, despite the election of a Liberal government in the ensuing election, Edgar was defeated in his own riding.

He entred private business and formed a railway company and attempted to build a line between Toronto and Lake Nipissing but failed in his attempt to win a contract. He used his experience to become the Liberal's Railway Critic when he returned to Parliament (and the Opposition benches) through an 1884 by-election.

In the 1880s, Edgar becamea vocal opponent of the Protestant Protective Association, an anti-Catholic political party associated with the Ontario Conservative Party. He argued in favour of tolerance and cooperation between English and French Canadians as well as Protestants and Catholics.

He also aruged against the concept of Imperial federation and for greater Canadian independence from Britain as well as in favour of reciprocity with the United States.

When the Liberals formed a government under Sir Wilfrid Laurier following the 1896 Canadian election, Edgar was nominated to become Speaker of the Canadian House of Commons and was also given a knighthood by Queen Victoria. Edgar was in poor health, however, and died in 1899 prior to the end of this term.