Patrick Robert Guiney (Parkstown, Co. Tipperary, Ireland, on 15 January 1835 – Boston, March 21, 1877) was an American Civil War soldier.
He was the second and eldest surviving son of James Roger Guiney, who was descended from Jacobites, and Judith Macrae. James Guiney, impoverished after a failed runaway marriage, brought with him on his second voyage to New Brunswick his favourite child Patrick, then not six years old. After some years, Mrs. Guiney rejoined her husband, recently crippled by a fall from his horse; a settlement followed in Portland, Maine, where the boy attended the public schools. He matriculated at Holy Cross College, Worcester, but left before graduating. His book-loving father having meanwhile died, he went to study for the Bar under Judge Walton, and was admitted in Lewiston, Maine, in 1856, becoming involved in criminal law.
In politics he was a Republican. For the Massachusetts Society for the Prevention of Cruelty to Animals, he won its first suit. In 1859 he married in the old cathedral, Boston, Janet Margaret Doyle, related to the Rt. Rev. James Warren Doyle, Bishop of Kildare and Leighlin. They had one son, who died in infancy, and one daughter, the poet and essayist Louise Imogen Guiney. Home life in Roxbury and professional success were cut short by the outbreak of the Civil War.
Familiar with the Manual of arms, Guiney enlisted for example's sake as a private, refusing a commission from Governor John A. Andrew until he had worked hard to help recruit the Ninth Regiment of Massachusetts Volunteers. Within two years (July, 1862), the first colonel having died from a wound received in action, Lieutenant-Colonel Guiney succeeded Young to the command. He won high official praise, notably for courage and presence of mind at the Battle of the Chickahominy, or Gaines's Mill, Virginia. Here, after three successive color-bearers had been shot down, the colonel himself reportedly seized the flag, threw aside coat and sword-belt, rose white-shirted and conspicuous in the stirrups, inspired a final rally, and turned the fortune of the day.