A pub (short for public house) is, in several countries, a drinking establishment licensed to serve alcoholic drinks for consumption on the premises. The term first appeared in England in the late 17th century to differentiate private houses from those open to the public as alehouses, taverns, and inns. Today, there is no strict definition, but the Campaign for Real Ale (CAMRA) states a pub has four characteristics:

The history of pubs can be traced to taverns in Roman Britain, and through Anglo-Saxon alehouses, but it was not until the early 19th century that pubs, as they are today, first began to appear. The model also became popular in countries and regions of British influence, where pubs are often still considered to be an important aspect of their culture. In many places, especially in villages, pubs are the focal point of local communities. In his 17th-century diary, Samuel Pepys described the pub as "the heart of England"; pubs have been established in other countries in modern times.

Although the drinks traditionally served include draught beer and cider, most also sell wine, spirits, tea, coffee, and soft drinks; many pubs offer meals and snacks, and those considered to be gastro-pubs serve food in a manner akin to a restaurant, and many pubs also host live music or karaoke.

A licence is required to operate a pub; the licensee is known as the landlord or landlady, or the publican. Often colloquially referred to as their "local" by regular customers, pubs are typically chosen for their proximity to home or work, good food, social atmosphere, the presence of friends and acquaintances, and the availability of pub games such as darts or pool. Pubs often screen sporting events, such as rugby, cricket and football; the pub quiz was established in the UK in the 1970s.

Ale was a native British drink before the arrival of the Roman Empire in the first century, but it was with the construction of the Roman road network that the first pubs, called tabernae (the origin of modern English "tavern"), began to appear.

After the departure of Roman authority in the fifth century and the fall of the Romano-British kingdoms, the Anglo-Saxons established alehouses that may have grown out of domestic dwellings, first attested in the 10th century. These alehouses quickly evolved into meeting houses for folk to socially congregate, gossip and arrange mutual help within their communities. The Wantage law code of Æthelred the Unready prescribes fines for breaching the peace at meetings held in alehouses.

A traveller in the early Middle Ages could obtain overnight accommodation in monasteries, but later a demand for hostelries grew with the popularity of pilgrimages and travel. The Hostellers of London were granted guild status in 1446, and in 1514 the guild became the Worshipful Company of Innholders. A survey in 1577 of drinking establishment in England and Wales for taxation purposes recorded 14,202 alehouses, 1,631 inns, and 329 taverns, representing one pub for every 187 people.

Inns are buildings where travellers can seek lodging and, usually, food and drink. They are typically located in the country or along a highway. In Europe, they possibly first sprang up when the Romans built a system of roads two millennia ago. Some inns in Europe are several centuries old. In addition to providing for the needs of travellers, inns traditionally acted as community gathering places.