Peter Sinclair (November 18, 1819 – October 9, 1906) was a Scottish farmer and politician in Prince Edward Island.

He represented Queen's County in the House of Commons of Canada from 1873 to 1878 as a Liberal member.

He was born in Glendaruel, Argyleshire, the son of Peter Sinclair, and came to Queens County, Prince Edward Island in 1840 with his mother.

Sinclair represented 1st Queens in the Legislative Assembly of Prince Edward Island from 1867 to 1873 and from 1882 to 1900 as a Liberal.

His sons Peter and John Ewen also later served in the House of Commons of Canada.