Cill Rialaig is a contemporary arts project, comprising the Cill Rialaig Artist Retreat and the Cill Rialaig Arts Centre with exhibition and retail facilities, founded by Noelle Campbell-Sharp in 1991 and managed by a registered charity. The operations are located a few kilometres apart, in the townlands of Cill Rialaigh and Dún Geágaín within the broad area of Ballinskelligs, on Bolus Head, County Kerry, Ireland. Since opening, the retreat has hosted more than 5,000 painters, writers, photographers, potters, composers, choreographers, and other artists, from a wide range of countries, on residencies. The project has been supported by prominent patrons, local and Dublin-based committees, representative art galleries in Dublin, and Irish state bodies such as Údarás na Gaeltachta, FÁS and the Arts Council.

The first stage of what became a multi-phase project was the Cill Rialaig Artist Retreat, founded by Noelle Campbell-Sharp, a former magazine publisher also active on Dublin's social scene. Campbell-Sharp, who had a holiday home in the area, was aware of a ruined 18th century village on Bolus Head on the Iveragh Peninsula in western County Kerry, which was threatened by a potential road-widening scheme, and proposed its reconstruction and dedication as a retreat for creative workers, including painters, photographers, composers and writers, from Ireland or elsewhere, to spend some quiet time in which to continue, or refresh, their work. The village had lost its last occupant in the 1950s, and the buildings were a mix of wholly disassembled and semi-collapsed.

Campbell-Sharp established a voluntary board, supported by a local golf committee, and social, wine appreciation and art auction committees in Dublin. She purchased the site for 30,000 pounds, with some of her own funds and support from friends (including Tony Ryan, Renata Coleman, Oliver Caffery and John O'Connor), and 6,000 pounds from the Irish National Lottery, and explained that she wanted to leave an enduring resource for the local people. She then applied for and secured planning permission for eight buildings.

During the early part of the development, she moved to the area to supervise, selling her home in Killiney, Dublin.

The project was planned and overseen by architect Alfred Cochrane. The foundation stone was laid by the Taoiseach, Charles Haughey, honorary patron of the project, on Saturday 21 September 1991. Other early patrons included John Bruton, John Hume and Dick Spring, as well as Bill Cullen, and support was given by Údarás na Gaeltachta and FÁS.

Work began with the construction of modern buildings on the sites of long-gone cabins, first two, at a cost of 50,000 Irish pounds each, then two more, then another, and two more later again. While made externally to conform to the pattern of the original houses, and reusing stone from the site, the new buildings were built with damp-proofing and insulation, small bathrooms, modern cooking facilities and storage heating, loft sleeping spaces, and concealed central skylights over the main studio work space. There were some questions about the project but much support from both artistic and local interests. The first two houses were ready in 1995. By 1998, still with two studio-cabins available, 180 artists had completed residencies, and by 2001, 600.

The conversation house and library was dedicated by President of Ireland Mary McAleese in 2008, to the memory of historic local storyteller (seannachai) Sean O'Connaill.

By 2011, 2500 artists had visited, and as of mid-2019, over 5,000.