Robert Knowlton Smith was a Conservative member of the Canadian House of Commons.
He was born in Amherst, Nova Scotia and became a barrister.
Smith studied at St. Francis Xavier University and the Dalhousie Law School where in 1911 he graduated with a Bachelor of Laws degree.
He was mayor of Amherst, Nova Scotia in 1923, and served on that municipality's council for five years. In August 1925, he was designated a Crown Prosecutor for Cumberland County, but resigned that October to seek federal office. He was first elected to Parliament at the Cumberland riding in the 1925 general election then re-elected there in 1926 and 1930.
On 16 January 1929, he was appointed King's Counsel through the Nova Scotia government. He died on 26 October 1973 and was interred at Parkview Cemetery in Waterloo.