John Dunn, first alcalde of Refugio and soldier and government official of the Republic of Texas, was a native of Ireland who probably lived in the United States before 1829, when he came to Texas. Under the customary liberal interpretation of Mexican colonization laws, Dunn, who was single but had servants, was considered the head of a family and given the lands of such. He was one of the earliest members of the Power and Hewetson colony. He operated a store near Nuestra Señora del Refugio Mission before the arrival of the Irish colonists in 1834. He met James Power and the colonists when they landed at El Cópano and carried to the jefe político at Bexar the official report of the arrival.
Upon the organization of the ayuntamiento of Refugio in 1834, Dunn became the first alcalde and was holding that office when Martín Perfecto de Cos and the Mexican army landed at El Cópano in September 1835. Having been notified by Power of Cos's expedition, Dunn dispatched messengers to the other colonies. He was a member of the committee of safety and correspondence of Refugio Municipality, was one of the party that accompanied Ira Westover to Goliad to assist George Morse Collinsworth, was a private in Capt. Philip Dimmitt's garrison from October 10, 1835, to January 10, 1836, and was in the Lipantitlán Expedition. On November 28, 1835, Dunn was elected to the select committee for the purchase of supplies for the revolutionary army. He signed the Goliad Declaration of Independence and was one of the committee of three that took the declaration to San Felipe de Austin.
In December 1836 Dunn was appointed first chief justice of Refugio County and entrusted with the political organization of the county. From his store's stocks he provided large quantities of dry goods and clothing to James W. Fannin's command. Sometime around mid-February 1836 he seems to have sold his business and for a short time joined Fannin's force at Goliad.
Dunn was a member of the mounted spy company commanded by Ewen Cameron, a unit organized in May or June 1836. On several occasions during the period of the republic he was commissioned to reorganize Refugio County, largely depopulated by the Mexican advance earlier that year. He was later a senator in the Second, Third, and Fourth congresses and a representative in the House of the Ninth Congress from Refugio County. He was chief justice of Refugio from 1845 to 1848 and was elected justice of the peace in 1850 but did not qualify for the place. He was in the mercantile business at Goliad and Refugio and was said to have taught school at one time. Dunn married about 1837 and was the father of three sons. He died on his ranch in Refugio County in January 1853.