Thomas Coulter (1793–1843) was an Irish physician, botanist and explorer. His passion for knowledge and discovery is thought to have been inspired by this father Samuel Coulter who had a remarkable collection of books on exploration, agriculture and bee-keeping, history, religion, and the Irish language.
Thomas was born at Carnbeg Farm on the outskirts of Dundalk, he attended the Classical and Mercantile Academy, a large boarding and day school located on Clanbrassil Street at that time. He went on to study and become a fellow at Trinity College Dublin and became an elected member of the Royal Irish Academy, which is still Ireland's leading body of experts in the sciences and humanities to this day.
After completing his medical degree in Dublin, Coulter studied botany in Geneva for seventeen months under Swiss taxonomist Augustin de Candolle. He then moved from Switzerland and became a physician with the Real del Monte Company in Mexico, during this period he collected and catalogued plants in the region.
He eventually left Mexico and travelled the world exploring many countries and conducting botanical research culminating in Arizona and Alta California in the early 19th century. He subsequently returned to Ireland in 1834 and became the founding curator of the herbarium at Trinity College, Dublin. Though he was a physician by profession, Coulter achieved success in different fields and is best remembered as a great explorer and a pioneer in botany.