Irish (Gaelic) male names come from the Irish language and early Gaelic tradition. Many use masculine morphological patterns such as the diminutive ending -án (seen across historic male names) and preserve internal consonants like bh, dh, and gh that affect pronunciation through lenition. A large share originate in early medieval Ireland, drawing on elements meaning color, character, or warfare, and from historical kings and saints. Examples include Diarmait, Donnchad, Dubhthach, Fedlimid, Ceallachan, Conary, Blaine, and Gavan.

In modern use, both traditional Gaelic spellings and Anglicized forms appear. Fadas (á, é, í, ó, ú) are used in Irish orthography, though many male names circulate without diacritics outside Ireland.