The surname Gaughan is derived from the Old Gaelic name Ua Gáibhtheacháin, which dates to before the 10th century. Its meaning is "male descendant of a fierce warrior". However, other translations claim it means "anxious one", demonstrating their expeditious and industrious nature. Historically, Irish families were named after the first chief of their tribe. In this case, it is evident that this clan descends from an illustrious warrior. Other derivatives of Ua Gáibhtheacháin are: O'Gaughan, Gavan, Gavaghan, Gavahan, Gavigan and Gahan.
As Old Ireland evolved, the surname O'Gáibtheacháin was shortened to O'Gacháin. This name was later anglicized into Gaughan.
As in most coats of arms, this crest's components reflect the character of its people. In the Gaughan coat of arms, the blue symbolizes their loyalty and thirst for truth, while the white represents their love of peace and serenity. The fish signify charity towards others and a truthful conscience. Furthermore, they are also associated with a desire for Jesus Christ to be one's spiritual nourishment. The ornate helmet included in the coat of arms indicates that they were men of high rank or gentlemen.
The history of Ireland in the 1650s is synonymous with Oliver Cromwell's pronouncement of fate for the Catholic population. The Gaughans were a chieftain tribe in Kilkenny until the Cromwellian conquest arrived to clear the way for Protestant colonization. Cromwell's transplantation and forced relocation from 1649 to 1680 impelled the Gaughans to flee Kilkenny. Those who survived the massacres were forced to settle in Connacht (County of Mayo).
They thrived in the west of Ireland, particularly County Mayo, where they possessed territory in the Crossmolina area. They are spoken of in the Annals of the Four Masters as chiefs of Calry in the barony of Tirawley.
- Bernadette Strachan, née Gaughan, English author of popular women's fiction
- Brendan Gaughan, American stock car driver
- Dick Gaughan, Scottish musician, singer, and songwriter
- Jack Gaughan, American Science Fiction Artist and illustrator
- Jack Gaughan Award for Best Emerging Artist
- Jackie Gaughan, casino owner and operator from the early 1950s in Las Vegas, Nevada
- John Gaughan, manufacturer of magic acts and equipment for magicians based in Los Angeles, California
- Kevin Gaughan, attorney and an advocate of government reform
- Michael Gaughan (businessman), casino owner and operator in Las Vegas, Nevada
- Norah Gaughan,American knitting designer and author
- Norbert Felix Gaughan, American Catholic bishop
- Patricia Anne Gaughan, a United States federal judge
- Michael Gaughan (Irish republican), Provisional Irish Republican Army (IRA) hunger striker
- Steven F. Gaughan, police officer in Prince George's County, Maryland
- Cunningham, John. "Conquest and Land in Ireland: The Transplantation to Connacht, 1649-1680". 2011.