Milnesville is a historic community of Markham, Ontario on the 8th Line or 8th Concession Road (now as Hwy.

48), between Elgin Mills Road and Major Mackenze Drive, and the Little Rouge Creek.

Milnesville was founded in 1851 by Peter Milne, who acquired lot 26, concession 7.

Because of his involvement in the uprising, Milne was arrested on March 21, 1838 and taken to Fort Henry in Kingston.

[2] In 1852, Milnesville was granted a post office which was run out of the general store operated by John Harrington.