Tiger Bay (Welsh: Bae Teigr) was the local name for an area of Cardiff which covered Butetown and Cardiff Docks. Following the building of the Cardiff Barrage, which dams the tidal rivers, Ely and Taff, to create a body of water, it is referred to as Cardiff Bay. Tiger Bay is Wales’ oldest multi-ethnic community, with sailors and workers from over 50 countries settling there from the mid-19th century onwards.

Cardiff Docks played a major part in Cardiff's development as it was the means of exporting coal from the South Wales Valleys to the rest of the world, helping to power the Industrial Age. The coal mining industry helped fund the growth of Cardiff to become the capital city of Wales, and contributed towards making the docks' owner, the 3rd Marquess of Bute, the richest man in the world at the time.

In 1794, the Glamorganshire Canal was completed, linking Cardiff with Merthyr, and in 1798 a basin was built, connecting the canal to the sea. Increasing agitation for proper dock facilities led Cardiff's foremost landowner, the 2nd Marquess of Bute, to promote the construction of the West Bute Dock, which opened in October 1839. Just two years later, the Taff Vale Railway opened. From the 1850s coal supplanted iron as the industrial foundation of South Wales, as the Cynon Valley and Rhondda Valley were mined.

As Cardiff's coal exports grew, so did its population. Well-appointed residential areas were created in the 1840s and early 1850s, centred around Mount Stuart Square and Loudoun Square (between West Bute Street and the Glamorganshire Canal) to house the growing numbers of merchants, brokers, builders, and seafarers from across the world settling close to the docks. The area, known as Tiger Bay from the fierce currents around the local tidal stretches of the River Severn, became one of the UK's oldest multicultural communities, with migrant communities from over 50 nationalities, including Norwegian, Somali, Yemeni, Spanish, Italian, Caribbean, and Irish. All the nationalities helped to create the multicultural character of the area, where people from different backgrounds socialised together and intermarried. Between the 1940s and 1968, the Cairo Café, run by Yemeni sailor Ali Salaman and his Welsh wife Olive, became a centre for Tiger Bay's diverse communities, providing a restaurant, a boarding house, and a mosque.

The East Bute dock opened in 1859. Coal exports from Cardiff Docks reached 2 million tons as early as 1862; by 1913, this had risen to 10,700,000 tons. Frustration at the lack of development at Cardiff led to rival docks being opened at nearby Penarth in 1865 and Barry in 1889. These developments eventually spurred Cardiff into action, with the opening of the Roath Dock in 1887 and the Queen Alexandra Dock in 1907. Coal exports from the South Wales Coalfield via Cardiff totalled nearly 9 million tons per annum, much of it exported in the holds of locally owned tramp steamers. The wealthier residents were able to move away to the new Cardiff suburbs. Butetown (particularly the area around Loudoun Square) became crowded, as families took in lodgers and split up the three-storey houses to help pay the rents.

Tiger Bay had a reputation as a tough and dangerous area; but locals who lived and stayed in the area describe a far friendlier place. Merchant seamen arrived in Cardiff from all over the world, only staying for as long as it took to discharge and reload their ships. Consequently, it has been said that the area became the red-light district of Cardiff, and many murders and lesser crimes went unsolved and unpunished, as the perpetrators had sailed away. In reality the primary brothels streets, and the primary red light area, were Charlotte Street and Whitmore Lane, both of which were outside Tiger Bay. They were demolished, and the site is now the Marriott Hotel car park.

By 1932, in the depths of the Great Depression which followed the 1926 United Kingdom general strike, coal exports had fallen to below 5 million tons, and dozens of locally owned ships were laid up. It was an era of depression from which Cardiff never really recovered, and despite intense activity at the port during the Second World War, coal exports continued to decline, finally ceasing in 1964.

Coal exports were key to the local economy, which began to decline in the 1960s, when exports from the docks stopped. Housing clearances in the 1960s relocated many of the residents of Butetown, previously the residential core of the docklands, into unpopular tower blocks. The economic decline in the 1960s and 1970s led to a 25% vacancy rate of buildings and 60% unemployment in Butetown. The infrastructure and buildings in the area declined: by the 1970s and 1980s the area required development and investment.