Bagillt is a small town lying on the Dee estuary in Flintshire, North Wales. It is bordered by Holywell to the west and Halkyn to the south, whilst the Dee estuary borders the north and east. Nearby towns and villages include Flint, Connah's Quay, Shotton, Chester, Halkyn, Rhosesmor, Greenfield, Mold and Buckley. The A548 passes through Bagillt, connecting it to Rhyl in the west and Chester in the east.

The church in Bagillt is dedicated to St Mary and dates back to 1837, although it was not completed until 1839. It is an attractive building, with a buttressed tower and attractive Victorian-style windows.

Lying near the town is Mostyn Hall. It is not known for how long a building has been present on the site, but since 1660 it has been the seat of the baronets of Mostyn, and since 1831, of the barons of Mostyn. In the 1840s the 1st Baron Mostyn commissioned Ambrose Poynter to remodel the existing house. This was carried out mainly in 1846–47 in Jacobean style.

During the late 18th century Bagillt grew as a prosperous mining and mill town, with an alkali and kindred factory producing lead, iron and zinc. The docks along the Dee were also important, since cargo was shipped from Bagillt to the north west of England from here. But by the 1930s the Great Depression in the United Kingdom had brought hardship and misery to the area as many of the manufacturing works and collieries were closed. Prior to World War II many people left in search of work, some moved to cities like Cardiff, Manchester and Liverpool while others went overseas to Canada and America.