Court tombs, sometimes called court cairns, are Neolithic megalithic structures, typically dating to around 4000 BCE or earlier, built from large upright stones and usually featuring an open, semicircular forecourt that leads into one or more roofed burial chambers. They are among the earliest evidence of organised communal burial in Ireland, and Mayo has a notable concentration of them, scattered across townlands whose names are often the only clue that anything remarkable lies nearby. Ballinillaun is one such townland.

The principal scholarly record for this tomb comes from the fieldwork of Ruaidhrí de Valera and Seán Ó Nualláin, whose Survey of the Megalithic Tombs of Ireland, Volume II, covering County Mayo, was published in Dublin in 1964. That survey remains a foundational document for understanding the distribution and structural variety of court tombs across the west of Ireland, and the Ballinillaun example was among those examined and catalogued within its pages. Beyond that, the notes available here are sparse, and the specific dimensions, condition, and precise configuration of this particular tomb are not detailed in what survives of the record. What can be said with confidence is that it was considered significant enough to be included in a systematic national survey carried out by two of the twentieth century's most careful students of Irish prehistory.