Sweetheart Abbey was founded in 1275AD as a Cistercian religious house. It was a daughterhouse of Dundrennan Abbey, and therefore referred to as "Novum Monasterium" ("new monastery"). The name "New Abbey" stuck, and the village remains so-named to the present day.

It was Lady Dervorguilla of Galloway who granted a charter in memory of her husband, John Balliol, who had died in 1268AD. Her love for him was so great that following his death, she carried his embalmed heart with her in an ivory box wherever she went. When she died, she was buried at the abbey, with the the casket containing the heart alongside her. The monks renamed the abbey "Dulce Cor" (Sweetheart Abbey) in tribute to her.

Sweetheart Abbey's first abbot - Abbott Henry - oversaw the construction of a magnificent church, complete with a large central tower, aisled naves, transepts containing chapels, and an open choir. The grounds were enclosed within a substantial precinct wall, rising to a height of 10 feet in places.

Unlike may of the Scottish border abbeys, Sweetheart Abbey didn't suffer damage and looting at the hands of invading English armies. The only incident of note occurred in 1300AD when Edward I ("the hammer of the Scots") took up residence here after sacking Caerlaverock Castle.

As a Scottish abbey, Sweetheart was unaffected by Henry VIII's dissolution of the monasteries. It even survived the Reformation, when Lord Maxwell refused an order to destroy the church in 1560AD. It wasn't until 1608AD that Catholic worship finally ceased at the abbey, and the last monks were forced to leave.

Subsequently, the church and its surrounding buildings were quarried for stone by the local community, and it slowly fell into a state of ruin. However, in 1779AD, pioneering local conservationists raised funds to purchase and preserve the church, as "an ornament to that part of the country". In 1928AD, their successors passed the abbey into the care of the state.

Today, much of the nave, choir and tower survive in a good state of repair. The precinct wall is also one of the most complete in Scotland, and the local red sandstone used in the construction of the church lends the buildings a distinctive colour and character. The setting is pleasant, although slightly marred by the proximity of the car park and adjacent road.