Dun is the common Irish word for fort, and the area around Doon is unusually thick with them. The Ordnance Survey maps eight ring forts in the village's surrounding townlands - the visible remains of Iron Age and early medieval farmsteads, each one a circular earthwork enclosing house sites for a single family or extended kin group. The largest sits directly behind the Church of Ireland church on the edge of the village. Saint Fintan founded a monastery in Doon in the early medieval period; his feast day, 3 January, is still kept locally. The first mention of Dun Bleisce in the surviving records came in 774 in the Annals of Inisfallen - one of the great chronicle compilations kept at Innisfallen monastery on a lake island in Killarney. The name's meaning has remained contested. "Bleisce" might be a small stream (fleisc) that runs through the village. It might be the name of an early Christian-era swineherd of a local chieftain. Or it might preserve the old Irish word for a woman of ill repute, around whose dwelling soldiers of some long-ago crown supposedly gathered.

Castle Garde, just outside the village, is older than most of what survives in east Limerick. It was originally built by the O'Briens - the great Gaelic dynasty descended from Brian Boru, the eleventh-century high king of Ireland - and was substantially restored in the early 1800s by Waller O'Grady, working with the architects James and George Richard Pain. The Pain brothers were also the architects of Mitchelstown Castle, the biggest neo-Gothic house in Ireland, completed in 1823. At Castle Garde they produced something more restrained but still distinctive: a circular keep, a square-plan tower, and crenellated parapets. Inside the gatehouse, the carved statues are particularly fine - representing Bacchus, Venus, and Athene, the Greco-Roman pantheon brought to a Limerick gate. The stone head over the main door represents Brian Boru himself, the local founder ancestor of the O'Briens, who united Ireland against the Norse before falling at Clontarf in 1014. Nearby Coonagh Castle is older still - a 13th-century structure surviving in ruins from the early Norman lordship of east Limerick.

Doon's two great educational institutions arrived in the second half of the nineteenth century, both at the urging of one Catholic priest. Rev. Patrick Hickey, the parish priest, had a grand-niece in the Convent of Mercy at Kinsale in County Cork. In February 1865 he invited her congregation to set up a convent in Doon. The first Sisters of Mercy arrived and began instructing children in the convent garden because they had no school building. The bishop of Cashel gave permission to build one in 1867, and Doon Convent Primary School opened in 1868. When Fr. Hickey died in 1864 he left property in his will to bring the Christian Brothers to Doon as well; Brother Walsh of Limerick selected two acres for the new monastery and school, and St. Fintan's Christian Brothers School opened in 1874. For nearly 150 years the two orders ran complementary schools - the Sisters teaching girls, the Brothers teaching boys. Both have closed: St. Fintan's CBS and St. Joseph's Mercy Secondary in 2013, after the amalgamation into Scoil na Trionoide Naofa, which opened on a new 15-acre site in 2014.

In July 2014 a torrential downpour broke over Doon. The hill above the village turned into a river of mud carrying tree trunks, boulders, and railway sleepers down through gardens and onto roads. People reported being trapped in cars and sheds, unable to reach their homes through the rain. Rivers burst their banks. Bridges were destroyed - including the one on the road to Kilcommon, which was still closed indefinitely a decade later. Many of the small east Limerick roads remained impassable for days. The mudslide became one of the more dramatic recent reminders that the gentle Limerick uplands - the foothills of the Silvermine and Slievefelim Mountains - can shed water and earth in volumes nobody quite expects. Climate change has made such events more frequent across Ireland, and Doon's experience that July became something of a local case study in what flash flooding can do to a hill village.

Doon GAA was founded in 1888, six years after the Gaelic Athletic Association itself. For more than a century the club's senior hurlers were in the upper ranks of Limerick hurling without ever winning the county championship. They reached the Limerick Senior Hurling final five times - losing to Ballybrown in 1989, Patrickswell in 2000, and Na Piarsaigh in both 2018 and 2020. The fifth final in October 2024 ended differently. Doon beat Na Piarsaigh and lifted the Daly Cup for the first time in 136 years. The match brought the whole village out. Five Doon players have won All-Ireland senior medals with Limerick between 2018 and 2023: Darragh O'Donovan (five), Ritchie English (four), Pat Ryan (four), Barry Murphy (one), and Adam English (one). Limerick's golden era under coach John Kiely has run through Doon as much as through any other club. Willie Moore from Doon played corner-back in the 1973 Limerick team that beat Kilkenny in the All-Ireland final. The village is small. The hurling is not.