The Least Tern (Sternula antillarum) commonly breeds along coastal beaches and major interior rivers of North America and the Caribbean. Least Terns have been observed in Hawai‘i since the 1970s; however, few breeding attempts have been documented. Nests have been discovered on the northwestern Hawaiian island of Midway Atoll and the southeastern Hawaiian island of Hawai‘i. While nesting is thought to also occur on the islands of O‘ahu and French Frigate Shoals based on observations of juvenile Least Terns, no observations of nests had been recorded for these islands prior to this study. In this paper we describe 2 accounts of discovering Least Tern eggs in the Ki‘i Unit of the James Campbell National Wildlife Refuge on O‘ahu, as well as several observations of breeding behavior in wetlands within the Pearl Harbor region of O‘ahu.