Community

The village takes its name from its parish church which is dedicated to the 2 Saints, St. Marcellus and Saint Marcellina. The church has medieval origins from the 12th century. It was wholly rebuilt in 1868 by a local Welsh architect, Goronwy Roberts. Llanddeusant is claimed to be the burial place of Branwen (Mabinogion). A cairn was discovered nearby and is now named 'Bedd Branwen' in Welsh. Branwen's grave is at the river (afon) Alaw.

Llynnon windmill

At Llanddeusant is Anglesey's and Wales' only working windmill, Llynnon Mill, opened in 1775 at a cost of £550 and renovated by the local council in 1986 and opened to the public. The mill was originally located there as it lies just to the north of the Afon Alaw, and a little west of Llyn Alaw. It also has the area's last working water mill, Melin Hywel.

School

The co-educational village primary school, Ysgol Gynradd Llanddeusant closed in July 2011 after serving the village for 160 years. On 2 October 2013, the Isle of Anglesey Council planning committee granted permission for the council to demolish the school and build 8 houses.

Notable people