Jurist and politician. Born in Forteviot (Perth and Kinross), the son of a clergyman, Robertson was educated at the University Edinburgh, graduating in 1864. He qualified as an advocate in 1867 and became a Queen's Counsel in 1885.
Robertson served as the Conservative Member of Parliament for Buteshire (1885-91). He was appointed Solicitor General for Scotland (1885), Lord Advocate (1888) and was made a Privy Counsellor in the same year. He was responsible for the important Local Government (Scotland) Act of 1889, which transformed the administrative landscape of the country, consolidating counties and improving their operation. He served as Lord President of the Court of Session, head of the judiciary in Scotland, from 1891-99 and was granted a life peerage as Lord Robertson of Forteviot. He received an honorary doctorate from the University of Edinburgh in 1890, and was appointed as their Rector in 1893. He also served as Chairman of the Irish University Commission.
Robertson retired to Muchalls Castle in Aberdeenshire.