Aedh (c. 840–878), sometimes spelt Aed or Aodh, became king of Scotland in 877 when he succeeded his brother Constantine I.

He was killed shortly after taking the throne by Giric, also known as Gregory the Great, who had conspired with Aed's nephew, Eochaid.

Not much is known of Aedh, or even if he was actually the one named by Constantine to hold the throne. Both Giric and Eochaid ruled jointly following Aedh's death.

Aedh did marry at some point in his life, but the details, including the date and place of the marriage, and the name of his wife are not known. One son, Constantine, ruled later (900–942/43), while another son, Donald, became King of Strathclyde in 908.

Aedh died violently in 878 at Strathallan. He may have been buried at Maiden Stone in Aberdeenshire. He was succeeded under the Scottish tanistry system by his nephew, Eochaid.