Background
He was born the son of Seymour and Louisa (née Graham) Leslie. His father worked in the Probate Office, London.
Member of the Senate of Northern Ireland
He was born the son of Seymour and Louisa (née Graham) Leslie. His father worked in the Probate Office, London.
Leslie studied at Gray"s Inn and briefly went into the law, before joining the Contract Department of the British Foreign Office.
He was appointed High Sheriff of Antrim in 1907. In 1907, he served as High Sheriff of Antrim. He resigned when given control of his family estates, and sat as an Irish Unionist Party councillor in County Antrim.
In 1921, he was elected for the Ulster Unionist Party to the first Senate of Northern Ireland, and served until his death in 1949.
Given his experience in drafting, he played a key role in maintaining the chamber as an institution capable of revising bills from the lower chamber. From 1945 to 1949, Leslie served as the Lord Lieutenant of Antrim.