Saad Saud Jan joined civil service of Pakistan in October 1953, as assistant commissioner. He opted for judicial career in 1959 as additional district and sessions judge. He also remained district and sessions judge Lahore. He also remained registrar High Court of West Pakistan and was appointed as joint secretary in Ministry of Law and Parliamentary Affairs in 1966.
He was elevated to the bench of Lahore High Court as an additional judge in 1971. He was appointed as Secretary in Parliamentary Affairs Division for preparation of the interim constitution of 1972 and returned to the High Court after the enactment of the 1973 Constitution. He also served as chairman, Punjab Services Tribunal, Member Election Commission of Pakistan, Member Board of Trustees of Lahore University of Management Sciences and acting Chief Justice. He was elevated to Supreme Court of Pakistan in October 1986 and retired in 1996.