Ogham is a Unicode block containing characters for representing Old Irish inscriptions.

Ogham /ˈɒɡəm/ (Modern Irish ˈoːmˠ or ˈoːəmˠ; Old Irish: ogam ˈɔɣamˠ) is an Early Medieval alphabet used primarily to write the early Irish language (in the so-called «orthodox» inscriptions, 4th to 6th centuries), and later the Old Irish language (so-called scholastic ogham, 6th to 9th centuries). There are roughly 400 surviving orthodox inscriptions on stone monuments throughout Ireland and western Britain; the bulk of them are in the south of Ireland, in Counties Kerry, Cork and Waterford. The largest number outside of Ireland is in Pembrokeshire in Wales. The vast majority of the inscriptions consist of personal names. According to the High Medieval Bríatharogam, names of various trees can be ascribed to individual letters. The etymology of the word ogam or ogham remains unclear. One possible origin is from the Irish og-úaim 'point-seam', referring to the seam made by the point of a sharp weapon.