St Mellons (Welsh: Llaneirwg) is a district of the city of Cardiff, Wales. As it lies east of the River Rhymney, it is traditionally in Monmouthshire, whereas most of the city to the west of the river, is in Glamorgan. It became part of the the city of Cardiff district of South Glamorgan under the Local Government Act 1972 on April 1, 1974.

St Mellons is one of the most respected villages in Cardiff with it being voted 2nd in the South Wales Echo top 20 towns in Wales.

The Area
The population of Old St. Mellons combined with Pontprennau in the 2001 census was just over 8,500, although that figure is expected to rise substantially by the 2011 census due to large scale housing developments in both suburbs. When most people refer to St Mellons they mean the modern housing estates built to the south and east of the old village, although this is technically within Trowbridge ward. The population of this area was approximately 7000 in 2001 and is also likely to rise substantially due to infill development along the mainline railway. There are also plans to regenerate some of the older council-owned estates in line with the recent trend of constructing three-storey town houses.

Facilities
There are a number of sports and leisure facilities, including floodlit outdoor basketball and football courts, numerous playing fields and children's playing parks as well as a bowls club, two community centres a job centre and a library

Schools
St Mellons has 4 public schools: St. Bishop Childs Church in Wales, Meadowlane Primary, Oakfield Primary and Willowbrook Primary. It also has St. Johns College, one of the best private school's in Cardiff, which, until the late 1970s was a Mental Institution known as Tyn-to-Bryn.

Pubs & Shopping
St Mellons is home to the second oldest pub in Cardiff - The Fox and Hounds, it also has 5 other pubs namely - The Bluebell Inn, The Heronmarsh, The Star Inn, The White Hart and The Willows.

There are 2 major retail complexes in St Mellons, including a Tesco and a Kwik Save. There is also a Texaco Petrol Station, a Car Wash, a Post Office, two unisex hairdressers, a Garden Centre, a Furniture Showroom, a Chemist, an Indian Takeaway, a Fish & Chip shop, Gift Shop, Bookmakers' and a number of small newsagents

Business
The St Mellons Business Park has a vast number of factories and offices which have been (or are still) inhabited by such companies as Gilesports, TBI, Bailey Homes and Lloyds Bank.

Transport
St. Mellons is located next to Junction 29a of the A48 (M)/Eastern Avenue Junction, where the A48 continues along Newport Road and the A48(M) rejoins the M4.

The entire of St. Mellons is a 30mph speed limit, except for a section of Newport Road which is 40mph. There are no permanent speed cameras in the area, although this is subject to change as the safety of the roads in the area have recently come under scrutiny following 3 deaths in 2 years.

There are no train facilities in the area, despite the local beauty spot Hendre Lake being just a stones throw away from the Freight Terminal Port. Train users will have to commute using a Bus from Cardiff city centre.

Cardiff Bus serve St Mellons via services 30, 44 and 45. Services run approximately every 9mins (Monday to Friday) via each stop, and will arrive in Cardiff in around 35mins. St Mellons is in Zone 4 of the Cardiff Bus system, with single adult fares to Cardiff costing �1.80, and a return (Day Rider ticket) �3.00

Wildlife
Despite the large number of new houses, a lot of wildlife can be seen especially to the eastern fringe: Foxes, Rabbits, Squirrels, Buzzards, Herons, Moorhens, Swans, Mallards, Woodpeckers and many other birds are a common sight.

Coastal Defences
Much of the newer parts of St. Mellons are only just above sea level. A system of drainage reens and sluice gates together with a sea wall which runs from the River Usk in the East to the Rhymney River in the West protect the area from the risk of coastal flooding