A messenger-at-arms is an officer of the ScottishCourt of Session, responsible for serving documents and enforcing court orders throughout Scotland. Messengers-at-arms must have a commission as a sheriff officer although, unlike sheriff officers, the jurisdiction of a messenger-at-arms is not limited to the area for which they have a commission. Both messengers-at-arms and sheriff officers are employed by private businesses and charge fees that are set by Act of Sederunt.
Originally known as an "Officer of the King", the office of messenger-at-arms dates back several hundred years. Messengers-at-arms have been under the control of the Lord Lyon King of Arms since at least 1510, and are still appointed by Lord Lyon, although now on the recommendation of the Court of Session, to execute summonses and letters of diligence connected with the Court of Session and High Court of Justiciary.