From Irish Gaelic 'Ó Sirideáin' meaning descendant of the searcher or seeker.
Sheridan is an Irish surname that crossed over into given-name use, carrying with it the history of the Ó Sirideáin clan — a Gaelic family name whose precise meaning is disputed but may derive from a word meaning "to seek" or possibly from a personal name Sirideán of uncertain origin. Surnames as first names have a long tradition in Anglo-Irish and Anglo-American naming, and Sheridan benefited enormously from association with one of the most famous names in the English theatrical tradition: Richard Brinsley Sheridan. Richard Brinsley Sheridan (1751–1816) was the Dublin-born playwright who gave the world The Rivals — in which the immortal Mrs.
Malaprop cheerfully mangled the English language — and The School for Scandal, perhaps the finest comedy of manners in the English canon. That Sheridan was also a Whig politician, a spellbinding orator, and a notorious rake, which meant the name absorbed associations of wit, eloquence, and a certain glamorous recklessness. Philip Henry Sheridan, the Union cavalry general who helped end the Civil War, added military valor to the name's American connotations.
In the twentieth century Sheridan worked as both a masculine and feminine given name, with the actress Ann Sheridan — the "Oomph Girl" of 1940s Hollywood — demonstrating its appeal across genders. Contemporary parents find in Sheridan a name that sounds distinguished without stiffness, Anglophone without being Anglo-Saxon, and literary without requiring explanation. It has a natural nickname in Sher or Sheri, but its full form is confident enough to stand alone.