Severn-Cotswold (or Cotswold-Severn) is a name given to a type of Megalithic chamber tomb built by Neolithic peoples in Wales and south west England around 3500 BC.

They consist of precisely-built, long trapezoid earth mounds covering a burial chamber. Because of this they are a type of chambered long barrow. In some examples, pairs of smaller burial chambers lead off from either side of the central rectangular burial chamber, itself connected to an anteroom. In others the entrance is a false entrance with the burial chambers accessed laterally from directly outside. A third group have merely a single large chamber.

Tombs of this type are concentrated in the Cotswolds but extend as far as Gower and Avebury with some isolated examples in North Wales. Tombs of all three types are generally evenly distributed and it has been theorised that the design evolved over time. Severn-Cotswold tombs share certain features with the transepted gallery graves of the Loire and may have been inspired by these, with the lateral chambers and other differences being local variations.

In the 1960s and 1970s Dr John Corcoran and others argued that the group in fact consisted of three contemporary types and later excavations have supported this.

Examples include Wayland's Smithy and West Kennet Long Barrow.