John A. O'Farrell (February 23, 1823 – October 29, 1900) was an Irish American adventurer, miner, and pioneer and was among the first residents of Boise, Idaho.

[1] O'Farrell returned to England in 1853 and enlisted in the British Navy during the Crimean War, serving aboard the Agamemnon, flagship of Admiral Lyons.

Leaving his wife in Philadelphia, he soon returned to mining in the western states and territories, and in 1863 he settled in Boise City, Idaho, becoming one of the town's original residents.

He constructed a cabin from cottonwood trees near the entrance to the newly rebuilt Fort Boise, on the road to Idaho City.

O'Farrell returned to Philadelphia then led a train of 14 wagons and members of his wife's family back to Boise City.

[7] In 1869, citing the Town Site Act of 1867, the United States General Land Office denied O'Farrell's claim to 442 acres that included the original plat of Boise City.