The Ollamh Érenn [ˈolaṽ ˈeːrʲenʲ] or Chief Ollam of Ireland was a professional title of Gaelic Ireland.
An ollam (literally 'most great') was a poet or bard of literature and history. Each chief or tuath had its own ollam. The head ollam of a province such as Ulster would have been the head of all the ollams in that province, and would have been a social equal of the provincial king.
Over all the provincial ollams was the Ard-Ollamh (Rí-Ollam, Rí-Eigeas, Príméces) who held the official post of Chief-Ollamh of Ireland or "Ollamh Érenn".
A modern equivalent in government would be a Minister for Education & Culture combined with the post of Poet Laureate.
His social status was equal to the High King of Ireland and he had his own palace and a large retinue of about thirty ollamhs together with their servants. The sumptuary laws allowed him to wear six colours in his clothes, the same as the king. The ollamh had a gold bell-branch held above him, the anruth had a silver bell-branch and the other poets had a bronze bell-branch. The post was partly hereditary, as Uraicecht na Ríar ("The Primer of the Stipulations", ed. Liam Breatnach, DIAS 1987) states that a poet can only attain ollamh-rank, if he stems from a family of poets (that is, if his father and grandfather had been poets). Originally the Ollamh was appointed by the king but by the 6th century A.D. it had become an elected post which was voted for by the other ollamhs.
An old Irish tale "Immacallam in dá Thuarad" ("The Colloquy of the Two Sages") gives an idea of the type of lofty speech of the chief ollamh.
Another old tale called "Tromdámh Guaire" ("The Heavy Company of Guaire")) or "Imtheacht na Tromdhaimhe" ("The Proceedings of the Great Bardic Institution")) gives a vivid description of the Chief Ollam with his entourage visiting the Irish chiefs.
In Lebor Gabala Erenn, an Ollamh is mentioned, named Ollamh Fodla. It relates "Ollamh Fodla, fierce in valour, Marked out the Scholar's Rampart, The first mighty king with grace, Who convened the Festival of Tara. Fifty years, it was tuneful fame, was he in the High Kingship over Ireland so that from him, with lucky freedom, Ulaidh received its name. He died a natural death within its capital."