A sawbuck is a device for holding rough wood so that it may be sawn into pieces of length usable in a stove or fireplace. Easily made in the field from rough material, it consists of two "X" forms, one at each end, which are stabilized by a central piece. The stock to be cut is placed in the upward facing "V"s of the end pieces where it may then be sawn.

A sawbuck is very simple to build. The five "V" sawbuck was designed with 10 vertical 2x4's each 4 feet long and 4 horizontal 2x6's 5 feet long using 3.5 inch wood screws. It was designed this way in order to cut two or more smaller pieces (2–4 feet in length) of firewood in rapid succession. A sawbuck should be heavy enough to negate any kickback from the chainsaw while cutting. Building a sawbuck that is too light weight could result in injury as it may tip over while cutting.

In Britain, unlike the USA, this is called a "saw horse"; a sawhorse in the U.S. is a similar device used (often in pairs) to support wood planks.

In the US, the term can also refer to a ten-dollar bill, from the Roman numeral interpretation of the 'X' shape of the device.