A leat (also spelled lete) is the name, common in the south and west of England, for a man-made watercourse, or makeshift aqueduct.

The most famous examples are Drake's Leat, constructed in 1591 under the management of Sir Francis Drake as an agent of the Corporation of Plymouth to carry water from Dartmoor to Plymouth, and the Devonport Leat constructed in the late 18th century to carry water to the expanding naval dockyard at Devonport (now a part of Plymouth). In addition to the two mentioned above, there are many leats on Dartmoor, mostly constructed to provide power for mining activities, although some were also sources of drinking water. The courses of many Dartmoor leats may still be followed - See the book "Follow the Leat" by John Robins ISBN 0950803006 first published 1982. For a full history of the leats which supplied Plymouth, England, see: "Water From the Moor" by David J. Hawkings ISBN 086114-788-X first published 1987. According to the Oxford English Dictionary, leat is cognate with let in the sense of "allow to pass through".

A leat is the artificial channel which supplies water to a watermill or its mill pond, collecting water from upstream of the mill so that the natural level of the driving water is above the level of the stream at the mill. Other names for the same thing include fleam (probably a leat supplying water to a mill that did not have a millpool). In parts of northern England, for example around Sheffield the equivalent word is goit.

Leat is also a birth given name.

See also

• Flume

Bodies of waterGeography of England AqueductsGiven names | Watermills