Thomas Marchildon (February 27, 1805 – May 17, 1858) was a businessman, farmer and political figure in Canada East.
Marchildon was elected to the Legislative Assembly of the Province of Canada for Champlain in 1851; he was reelected in 1854 as a member of the parti rouge.
In 1858, he was defeated in the same riding by his cousin, Joseph-Édouard Turcotte.
He opposed the construction of the North Shore Railway.
He was believed to have suffered an attack of apoplexy although some people thought that he had committed suicide; the coroner found that his death had been accidental.