The village takes its name from the two mills that once stood on the River Clare. Baile an Mhuilinn, the town of the mill. O'Grady's mill at Milltown itself was demolished in the 1950s during the Corrib River Drainage Scheme. The other - Birmingham's mill, a corn and tuck mill at Lack - is still visible in ruins along the river. The 1850s valuation records describe it as having one pair of mill stones and a water wheel fourteen feet in diameter, valued at £2. John Farrell was the resident miller. The parish itself - Adergoole and Liskeevy combined - has medieval origins, with the first historical reference to Milltown going back to 1589, when Sir Murrogh O'Flaherty came down with his clansmen, burned half the village, destroyed the castle's grainfields, failed to take the castle itself, and on the way back to Cong burned sixteen other villages and drove off three thousand head of cattle. It was, by 16th-century standards, an ordinary military raid.

On the edge of the parish stand the ruins of Kilclooney Castle, once home to the O hUigin family - one of the great bardic dynasties of Gaelic Ireland. Domhnall O hUiginn lived there in 1574. The 16th-century poet Tadhg Dall O hUiginn referred to a school of poetry at the site. The school took students - seventeen of them at one time from Ulster's brightest, by one account, with some reputed to have come from Scotland - for a course in filiocht, Irish poetry, that lasted twelve years. The school year ran from November to March, the dark half of the year. Each student is said to have had his own stone hut where he could meditate alone on an assigned theme before reciting his composition to his tutor and his fellow students the following day. The huts are gone. A large portion of the tower house still stands, in ruins.

The Irish War of Independence left two ambush sites in Milltown's local memory. The Egg Shed Ambush, April 1921: ten to twelve volunteers attacked two RIC constables returning from patrolling the railway station, trying to take their rifles. Armed police and Black and Tans rushed from the nearby barracks and the rifles were recovered. The Cnocan Mor Ambush, 27 June 1921: a seven-man flying column under Tom Dunleavy lay in wait on the Milltown-Tuam road for a combined RIC and Black and Tan patrol. Two were killed: Sergeant James Murrin, who should have retired the previous week but for a paperwork problem, and Constable Edgar Day, a young man from Nottingham. The reprisals were severe - the Hannon family's home at Belmont was burned to the ground; the Flannery house in Liskeavy nearly so. During the subsequent Civil War of 1922 to 1923, the Grand Gates Ambush at Milbrook House saw a petty sessions clerk named James McDonagh, suspected of being a police spy, killed by local Fenians as he walked home drunk. The man who organised it, a barman named Roche, emigrated to America shortly afterward to avoid prosecution.

The Milltown Races date to 1877. Earlier race meetings ran in the 1840s on St Patrick's Day, then moved to Easter Monday for better weather. The Tuam Herald once reported of the races that porter ran in rivers down countless throats and corked concoctions sold by the million. By the 1930s the races were declining; they were abandoned during the Second World War, revived briefly in 1952, and held for the last time in 1966. A two-week carnival was organised in 1957 to boost attendance, with popular showbands of the day; rising costs eventually killed it in 1981. Handball, in the 1920s and 1930s, was more popular in the village than football - the alley was occupied all day Sundays and through long summer evenings - until the Second World War made handballs impossible to obtain and the sport never recovered. Milltown GAA, founded 1953, has won the Galway Senior Football Championship twice, in 1971 and 1981.

Milltown's roll of notable sons and daughters is long for a village of its size. John Birmingham (1816-1884), the astronomer who first detected the recurrent nova T Coronae Borealis in 1866. Patrick Duggan (1813-1896), Catholic bishop. Richard W. Dowling (1838-1867), the Confederate commander at the Second Battle of Sabine Pass during the American Civil War. Micheal O Lochain (1836-1899), founder of the Philo-Celtic Society in the United States and a key figure in the Irish-American Gaelic revival. The playwright M.J. Molloy (1914-1994). Sabina Higgins, former actress and First Lady of Ireland. The poet, journalist and television presenter Jim Carney. The footballer Noel Tierney, All-Ireland winner with Galway in 1964, 1965, and 1966. Birmingham's own telescope is on display in the village community museum, alongside the artefacts of a small place with a long memory. The Lurgan Canoe is in Dublin, where the museum keeps it dim and humid to slow what the bog could no longer slow.