Mather Byles DesBrisay (March 19, 1828 – April 8, 1900) was a Canadian lawyer, judge, politician, and historian in the Province of Nova Scotia whose collections form the DesBrisay Museum in Bridgewater, Nova Scotia. In 1867, DesBrisay entered provincial politics as part of the anti Confederation movement and in the Nova Scotia general election was voted to the Nova Scotia House of Assembly. Reelected in 1874, the following year he was named Speaker of the House of Assembly of Nova Scotia. After 1875 DesBrisay was out of politics and in 1876 he married Ada Adams Harley.