David Scott Armstrong (born July 9, 1966) is a Canadian politician, who was elected as a Conservative member to represent the electoral district of Cumberland—Colchester—Musquodoboit Valley in the federal by-elections on November 9, 2009.

[7] Following the resignation of then independent Bill Casey in April 2009 as the Member of Parliament for Cumberland—Colchester—Musquodoboit Valley,[8] Armstrong was nominated as the Conservative Party candidate for the byelection to replace him.

[12] In September 2012, Armstrong was named chairman of the federal Conservative Atlantic caucus, replacing New Brunswick MP Mike Allen.

[18] After his defeat and because the Conservatives did not elect a single MP in the 32 seats of Atlantic Canada during the 2015 election, Armstrong was appointed Official Opposition Critic for Atlantic Canada and ACOA by Acting Conservative Leader of the Opposition Rona Ambrose.

Armstrong worked as a paid staffer in the office of the Leader of the Opposition and spent his time between Ottawa and Atlantic Canada but was based in Nova Scotia.

[2] He re-contested the riding of Cumberland—Colchester in the 2019 federal election but lost narrowly to Liberal candidate Lenore Zann.

[20] On October 21, 2024, Armstrong was nominated as the Progressive Conservative candidate in Colchester-Musquodoboit Valley for the next Nova Scotia provincial election.