Taff's Well is situated 6 miles (9.7 km) from Cardiff city centre in South Wales. It lies on the banks of the river Taff, and straddles both the river Taff and the county boundary. Although much of Taff's Well is geographically in Cardiff the town is under the administrative authority of Rhondda Cynon Taf. The river Taff rises as the Taf Fechan and Taf Fawr in the Brecon Beacons and meets at Merthyr Tydfil, before flowing onwards to its estuary at Cardiff Bay.

Taff's Well is known as the 'smallest spa in the world', and it is the well that once stood near the river which gives the village its name. The water has been taken since Roman times and was believed to cure muscular rheumatism.

The town is basically a suburb of Cardiff and residents regularly commute to the City centre. There are regular bus services to and from Taff's Well, with the Stagecoach bus 132 travelling to Cardiff central bus station. Northbound train services go to Aberdare, Treherbert, and Merthyr Tydfil via Pontypridd, whilst southbound trains travel to Cardiff Central and Cardiff Queen Street.