Glan Llyn is a mixed-use community development south-east of Newport, South Wales, at the western end of the former Llanwern steelworks, on the A4810 road at the edge of the Caldicot Levels.

After the closure of steel production, Corus Group sought a redevelopment partner; they chose St. Modwen Properties, who in 2004 bought a 600-acre (240 ha) package of land.

The first phase was approved in April 2010 by Newport City Council; this is to create 1,330 homes, the district centre, a primary school and the west lake.

[2] After gaining specific planning permission in April 2011,[5] Persimmon plc started work on the construction of the first 307 homes in September 2011.

Due to its proximity to the M4 and the Second Severn Crossing, and relatively low property prices (compared to South West England) it has proved to be very popular with commuters working in Bristol.