William Austin Burt (June 13, 1792 – August 18, 1858) was an American scientist, inventor, legislator, millwright, justice of the peace, school inspector, postmaster, judge, builder, businessman, surveyor and soldier. He first was a builder of sawmills, but his main interest was that of surveying. Burt built sawmills in an area that is now the city of Port Huron, Michigan. He built an excellent reputation for his accurate surveying work on public lands. He became a government deputy surveyor and trained many young men in several states how to become professional surveyors. Burt surveyed boundaries in the states of Michigan, Wisconsin, Minnesota, and Iowa starting as early as 1833. He involved his five sons in surveying and each became a government deputy surveyor.

Burt was a promoter of the construction of the Sault Ste. Marie Canal, a shipping navigational lock to bypass the rapids on the St. Marys River. He contributed in its surveying and construction. In addition he was associated with the surveying of the Upper Peninsula of Michigan in general. He was the prime surveyor that settled the boundary disputes between Michigan and Wisconsin.

He was an inventor and patented several key items in the 19th century, derivatives of which are still being used in the 21st century. His 1829 typewriter is the first constructed in America with a patent. It was later destroyed in a fire. His great grandson built a model of it for the 1893 Chicago's World's Fair based on a parchment copy of the original patent. This model went through various hands and ended up at the Smithsonian Institution in Washington, D.C.

Burt's solar compass for surveying was invented out of need for a compass that was not affected by large iron deposits in a land district. He first encountered in Michigan the problem of the needle in a normal magnetic compass fluctuating erratically in all directions. This interference of course didn't allow surveying of the area. This was due to a large deposit of iron ore in Marquette County, Michigan. It turned out to ultimately be the Marquette Iron Range and mining towns sprung up in the county to get the iron ore.

Burt's equatorial sextant for navigation was invented out of need for an accurate way to know exactly where a ship was located in the world. He applied the basic design of his solar compass of using the sun as a reference and could determine a ship's azimuth, altitude, time, and declination with greater accuracy than the normal magnetic compass then used.