Lieutenant-Colonel Sir Ronald Deane Ross, 2nd Baronet MC (13 July 1888 – 31 January 1958) was an Ulster Unionist Northern Irish Member of Parliament (MP).

He was the only son of Sir John Ross, 1st Baronet, the last judge to hold the office of Lord Chancellor of Ireland, and Katherine Mary Jeffcock.

He resigned his commission in 1938, but rejoined his regiment in 1939 and served in the Second World War, reaching the rank of lieutenant-colonel.

He was elected unopposed to the British Parliament in 1929 in a byelection for the Londonderry constituency, a seat once held by his father.

He was returned again in 1945 and again in 1950 with majorities of 50.75% and 62.59% respectively, before resigning his seat in 1951, triggering an uncontested by-election which was won by the Ulster Unionist Party.