The Breadknife is a volcanic dyke in New South Wales, Australia. It is nearly 850 metres high, but often is only 500 m wide, which is particularly rare. The Breadknife was part of a large shield volcano, that first erupted about 18 million years ago and stopped about 15 million years ago. This shield volcano rose about 1,000 m and is now largely eroded, forming the Warrumbungles. The Breadknife was formed when hot magma spread through a soft rock. When the magma solidified and became harder than the soft rock, erosion exposed a beautiful dyke.
A network of walking tracks are used to access the steep mountains and ridges surrounding the dyke. Nearby volcanic remnants include the Belgourie Spire, Belgourie Split Rock, Crater Bluff, Bluff Mountain and Mount Exmouth. The shortest walk completely around the Breadknife is hard and steep, taking roughly five hours to complete.