Also known as St Oran’s Graveyard, this burial ground has been in use for many centuries. Early-Christian gravemarkers found here, and now on display in the abbey’s infirmary museum, suggest that it has been in use since the 8th century. It is the legendary burial place of early Scottish kings and at least 7, including Kenneth mac Alpin (858), seem to have been buried here. In later centuries, the chiefs of powerful clans also made this their final resting place, including those of the MacKinnons, MacLeans and MacLeods. Reilig Òdhrain continues to be an active graveyard and in 1994 John Smith, former leader of the labour party, was interred here.
You can find more information about Iona Abbey at Historic Scotland's Iona History site.