Nicholas Fagan (abt 1785–1852) was a prominent figure in the history of Refugio County, Texas, known for his contributions as a blacksmith, rancher, Texas patriot, and pioneer during the early 19th century. He hoisted Texas' first flag of independence, Dimmitt's "bloody arm flag," after the signing of the Goliad Declaration of Independence. Nicholas was spared execution twice, once at Refugio and once at Goliad, by José de Urrea's men due to his close friendship with Carlos de la Garza, a Captain in the Mexican army.

Fagan was most likely born in County Westmeath, Ireland, but most sources site County Meath. His parents were James and Annie Fagan. He grew up alongside cousin, General Edward Pakenham from Castlepollard, County Westmeath, who died in the Battle of New Orleans. He immigrated to the United States in 1816 or 1817 with his first wife, Kate Connelly, and his daughter, Annie Fagan. Arriving originally in New York, the family moved through Philadelphia, Pittsburgh, Cincinnati, and St. Louis. During this time period, Kate and Nicholas had another child, Mary. The family moved to an area north of St. Louis for three years, having a third child, John, in 1823.

Devoutly Catholic, the family moved to New Orleans so the children could attend a Catholic church around 1823. The family traveled by flat boat down the Mississippi river with all their possessions. Soon after arriving, they contracted yellow fever and Kate died. A good Samaritan, Madame Duplice, took the children into her home and cared for them for some time. Meanwhile, Nicholas met a widow, Catherine Hanselman Balsch, originally from Stuttgart. They were married in New Orleans in 1824. The couple had two daughters and a son, before "Texas fever" struck Nicholas to move to Texas.

Fagan went to Copano, Texas, to scout the area for water, building materials, and an appropriate farmstead location prior to bringing his family. He found a suitable location on the south bank of the San Antonio River in what is now Refugio County, then retrieved his family.

Fagan, his family, and two other families arrived in Texas on the ship Panoma. A Captain named Prietta had secured a special permit for the families to land at Copano. The Fagans were among the earliest settlers of Power and Hewetson's Colony, which was established with the purpose of settling the sparsely populated Mexican frontier with Irish Catholics.

Fagan soon met Carlos de la Garza, whose ranch was across the river and a few miles to the west. de la Garza provided some animals to Fagan to help him get started and informed him of a wrecked Spanish barkentine 20 miles away with good lumber for building a house. Fagan built his ranch house out of the wrecked ship.

Fagan built the first mill in the area and provided flour, corn meal, and masa for the local ranches. The family lived amongst the local Karankawa people and had generally friendly relations before the Texas Revolution. The Karankawas shared beer with Fagan's children, harvested crops, and attended Annie Fagan's wedding.

On August 4, 1834, five years after establishing his homestead, Fagan received his land grant of 9,538 acres, part of the Power and Hewetson Colony.