Dorcas Blackwood, 1st Baroness Dufferin and Claneboye (born Dorcas Stevenson; 1726 – 8 February 1807) was the eldest daughter and co-heir of James Stevenson, of Killyleagh, County Down, and his wife Ann, née Price, daughter of General Nicholas Price.

Her paternal grandparents were Hans Stevenson and his wife Anne, née Hamilton.

Her grandmother was the second daughter and eventually sole heiress of James Hamilton of Neilsbrook, County Antrim.

Her husband succeeded his father, Sir Robert Blackwood, as baronet and was member of parliament for Killyleagh, and later for Bangor.

[1] She died on 8 February 1807 and was succeeded by her second son, James, who became 2nd Baron Dufferin and Claneboye.