Pierre St-Jean (September 23, 1833 – May 6, 1900) was a Canadian doctor and politician.

During the 1840s, he established a French language literary society there with J.B. Turgeon.

He served four terms as president of the L'Institut canadien-français d'Ottawa.

In 1874, he became the first French-speaking member from Ontario in the House of Commons of Canada, representing Ottawa City.

[1] During his term as mayor, the Canada Atlantic Railway link to Ottawa was completed.