Witney is a market town on the River Windrush in West Oxfordshire in the county of Oxfordshire, England. It is 12 miles (19 km) west of Oxford.

The place-name "Witney" is derived from the Old English for "Witta's island". The earliest known record of it is as Wyttannige in a Saxon charter of 969. The Domesday Book of 1086 records it as Witenie, in the ancient hundred of Bampton.

The Church of England parish church of St Mary the Virgin was originally Norman. The north porch and north aisle were added in this style late in the 12th century, and survived a major rebuilding in about 1243. In this rebuilding the present chancel, transepts, tower and spire were added and the nave was remodelled, all in the Early English style. In the 14th century a number of side chapels and some of the present windows were added in the Decorated style. In the 15th century the south transept was extended and the present west window of the nave were added in the Perpendicular style. The tower has a peal of eight bells. The tower of the church is 69 feet (21 metres) high, topped by a tall and slender spire, which brings the total height of the church to 154 feet (47 metres).

Holy Trinity Church, Wood Green, was built in 1849 in a Gothic Revival rendition of Early English Gothic. St Mary the Virgin and Holy Trinity are now members of a single team parish.

The Friends Meeting House in Wood Green was built in the 18th century. Since 1997 Quakers in Witney have met at the Corn Exchange. The Methodist church in the High Street was built in 1850. It is now one of five Methodist churches and chapels in Witney. The Roman Catholic parish of Our Lady and Saint Hugh was founded in 1913. It originally used a chapel in West End built in 1881 but now has its own modern building. The old chapel in West End is now Elim Christian Fellowship. Witney High Street still has several older buildings, which are protected by the Witney and Cogges conservation area.

Witney Market began in the Middle Ages. Thursday is the traditional market day but there is also a market on Saturday. The buttercross in the market square is so called because people from neighbouring towns would gather there to buy butter and eggs. It was built in about 1600 and its clock was added in 1683. Witney Town Hall, which is arcaded on the ground floor and has an assembly room on the first floor, was completed in 1786. Witney has long been an important crossing over the River Windrush. The architect Thomas Wyatt rebuilt the bridge in Bridge Street in 1822.

Witney workhouse was on Razor Hill (now Tower Hill). It was designed by the architect George Wilkinson and built in 1835–36. It had four wings radiating from an octagonal central building, similar to the Chipping Norton workhouse, which also was built by Wilkinson. His younger brother William Wilkinson added a separate chapel to Witney Workhouse in 1860. In the First World War the workhouse held prisoners of war. In 1940 the workhouse was converted into Crawford Collets engineering factory under the direction of Leonard Frank Eve. The chapel was made the factory canteen. In 1979 Crawford Collets had the main buildings demolished and replaced with a modern factory, but preserved the entrance gate and former chapel. In 2004 the modern factory was demolished for redevelopment. The gate and chapel have again been preserved and the former chapel converted into offices.

There are three tiers of local government covering Witney, at civil parish (town), district, and county level: Witney Town Council, West Oxfordshire District Council, and Oxfordshire County Council. The town council has its offices at Witney Town Hall and meets at the Corn Exchange. West Oxfordshire District Council is also based in the town, having its main offices on Woodgreen.