Abingdon-on-Thames, commonly known as Abingdon, is a historic market town and civil parish on the River Thames in the Vale of the White Horse district of Oxfordshire, England. The historic county town of Berkshire, the area was occupied from the early to middle Iron Age and the remains of a late Iron Age and Roman defensive enclosure lies below the town centre. Abingdon Abbey was founded around 676, giving its name to the emerging town. In the 13th and 14th centuries, Abingdon was an agricultural centre with an extensive trade in wool, alongside weaving and the manufacture of clothing. Charters for the holding of markets and fairs were granted by various monarchs, from Edward I to George II.

The River Thames, known alternatively in parts as the River Isis, is a river that flows through southern England including London. At 215 miles (346 km), it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn.