Llansilin (Welsh pronunciationⓘ) is a village and community in Montgomeryshire, Powys, Wales, 5 miles (8 km) west of Oswestry.

The village was a primary location for the making of the film The Englishman Who Went Up a Hill But Came Down a Mountain, which starred Hugh Grant.

The earliest part of the present building dates from the 13th century, although there had been a church on the site from much earlier times.

[5] Owain Glyndŵr, the last native Welshman to hold the title Prince of Wales (Tywysog Cymru), was born and had his palace in the motte and bailey castle at Sycharth in the parish.

German Neoclassical metal guitarist Uli Jon Roth has a home in Llansilin.