Gwalchmai is a village on Anglesey in north Wales, within the Trewalchmai community. The community's population in the 2011 census was 1009. The village is considered to be named after the 12th-century court poet Gwalchmai ap Meilyr, whose own name may be derived from that of the Welsh hero known as Gwalchmei ap Gwyar, who became the Gawain of later Arthurian legend.