The following report describes the results of an archaeological excavation at Killarainy 1 (Registration No.: E4575 and under Ministerial Directions A067), which was located along the route of the N59 Moycullen Bypass in County Galway. The site at Killarainy 1 was discovered during advance archaeological testing undertaken in 2014 by IAC Ltd (Ryan 2014; Registration No.: E4512). Stage (iii) excavation work at Killarainy 1 was undertaken from the 23 to 25 of October 2014. Killarainy 1 was a large irregular pit. It was backfilled with clay and stones and contained some evidence that the stones were scorched probably before they were dumped in the pit. There was no obvious function for the pit. It may have been a quarry pit that was backfilled or possibly a large cut for the erection of a post associated with the nearby prehistoric activity represented by the burnt mounds of Killarainy 3 and Killarainy 4. Post-excavation analysis of charcoal recovered from the fill of the pit C6/S1 indicated that hazel was the only species present. The function of the feature is unknown. A single find, a retouched artefact classified as a sub?circular convex scraper was recovered from topsoil at Killarainy 1. Dating the activity at Killarainy 1 on the basis of a single artefact type is problematic, however, this find would not be uncommon in a Neolithic or Early Bronze Age context.