Richard D'Alton Williams (8 October 1822 – 5 July 1862) was an Irish physician and poet, "Shamrock" of the Nation.
He grew up in Grenanstown, a townland near the Devil's Bit in County Tipperary, where his father farmed for Count Dalton.
In 1848, with Thomas Antisell and Kevin O'Doherty, he brought out a newspaper, The Irish Tribune, to take the place of the suppressed United Irishman, founded by John Mitchel.
On 30 October 1848, at a third trial, O'Doherty was convicted and transported to Australia; Antisell fled to the US, arriving in November.
His headstone was later erected that year by Irish members of the 8th New Hampshire Volunteer Infantry, then encamped in Thibodaux.