The Church of Our Lady of the Sea was built using reinforced concrete around 1937 and its dedication carries tribute to sailors lost at sea. The roof is designed to resemble the hull of a boat, and the windows in the crypt port holes. These aspects reflecting the maritime heritage of Amlwch.

Designed by G Rinvolucri, an Italian architect who was originally brought to Wales as a prisoner of war. He subsequently married a local woman, and lived and worked in north Wales, specialising in Roman Catholic churches. He also designed a number of other churches in Wales, including those at Abergele, and Porthmadog.

J Hill, RCAHMW, 09 February 2004

The church closed in 2004 due to deterioration to the concrete, but was restored in 2010 and reopened in May 2011 - RCAHMW, 2016.