Since the 17th century the United Kingdom has been one of the world's largest consumers of tea, with an average annual per capita consumption of 1.9 kilograms (4.2 lb). Originally an upper-class drink in Europe, tea gradually became common through all classes. It is considered an important part of the British identity and is a prominent feature of British culture and society. Tea remained more popular than coffee in Britain until around 2016 according to the "Economist".

In Northern Ireland and in the rest of the United Kingdom tea drinking blends and preferences vary. Although typically served with milk, it is also common to drink certain varieties black or with lemon. Sugar is a popular addition to any variety. Everyday tea, such as English breakfast tea, served in a mug with milk and sugar is a popular combination. Sandwiches, crumpets, scones, cake, or biscuits often accompany tea; afternoon tea is a meal in which sandwiches, bread and butter, cakes and biscuits are typically served.

The rise in popularity of tea between the 17th and 19th centuries had major social, political, and economic implications for the Kingdom of Great Britain. Tea defined respectability and domestic rituals, supported the rise of the British Empire, and contributed to the rise of the Industrial Revolution by supplying both the capital for factories and calories for labourers. It also demonstrated the power of globalisation and its ability to transform a country and reshape its society.

William H. Ukers argues in All About Tea: Volume I that tea gained popularity in Great Britain due to its reputation as a medicinal drink and its burgeoning presence in coffeehouses where elite men congregated. As for the popularity of tea among women, he briefly acknowledges that Princess Catherine of Braganza, the future queen consort of England, made tea fashionable amongst aristocratic women, but largely attributes its popularity to its ubiquity in the medical discourse of the 17th century. In Empire of Tea: The Asian Leaf that Conquered the World the authors Markman Ellis, Richard Coulton and Matthew Mauger trace tea's popularity back to three distinct groups: virtuosi, merchants, and elite female aristocrats. They argue that the influence of these three groups combined launched tea as a popular beverage in Britain.

Woodruff D. Smith in his article "Complications of the Commonplace: Tea, Sugar, and Imperialism" differs from the beliefs of the previous writers. He argues that tea only became popular once sugar was added to the drink and that the combination became associated with a domestic ritual that indicated respectability. Sidney W. Mintz in both "The Changing Roles of Food in the Story of Consumption" and Sweetness and Power agrees to an extent with Smith, acknowledging that sugar played a monumental role in the rise of tea, but he contradicts Smith's connection of tea to respectability. While Smith argues that tea first became popular in the home, Mintz claims that tea was drunk during the workday for its warm sweetness and stimulating properties, elaborating that it was later that tea entered the home and became an "integral part of the social fabric".

The history of European interactions with tea dates back to the mid-16th century. The earliest mention of tea in Western literature was by Giambattista Ramusio, a Venetian explorer, as Chai Catai, or "Tea of China", in 1559. Tea was mentioned several more times in various European countries afterwards, but Jan Hugo van Linschooten, a Dutch navigator, was the first to write a printed reference of tea in English in 1598 in his Voyages and Travels.

However, it was several years later, in 1615, that the earliest known reference to tea by an Englishman took place. In a letter, Mr. R. Wickham, an agent for the East India Company stationed at Japan, asked a Mr. Eaton, who was stationed in then-Portuguese Macao, China, to send him "a pot of the best sort of chaw", phonetically an approximation of "chàh", the local Cantonese dialect word for tea. Another early reference to tea appears in the writings of the cleric Samuel Purchas in 1625. Purchas described how the Chinese consumed tea as "the powder of a certaine herbe called chia of which they put as much as a walnut shell may contain, into a dish of Porcelane, and drink it with hot water". In 1637 Peter Mundy, a British traveller and merchant who came across tea in Fujian, China, wrote, "chaa – only water with a kind of herb boyled in it".

Though there were a number of early mentions, it was several more years before tea was actually sold in England. Green tea exported from China was first introduced in the coffeehouses of London shortly before the 1660 Stuart Restoration.