Duncan Alexander Ross (November 4, 1873 – 1954) was an Ontario farmer and political figure.
He represented Glengarry in the Legislative Assembly of Ontario from 1919 to 1923 as a United Farmers member.
Ross married first Jemima Dingwall and second Laura Clifford McGregor.
He was a director for the Glengarry Mutual Fire Insurance Company.
He died in 1954 and was buried at North Branch Cemetery in Martintown, Ontario.