William Austin Burt (June 13, 1792 – August 18, 1858) was an American inventor, legislator, surveyor, and millwright.

Burt was born in Worcester, Massachusetts, and lived in Michigan from 1822 until his death in 1858. He was a member of the Michigan Territorial Legislature, 1826-1827. He served as Mount Vernon's first postmaster from 1832 to 1856. He was a Macomb County Circuit Court judge in 1833, a state legislator in 1853, and a deputy U.S. surveyor from 1833 to 1853. While surveying, he won acclaim for his accurate work on public land surveys. In 1857, Burt moved to Detroit, where he died a year later.

Among Burt's numerous inventions were the typographer in 1829, which was a predecessor to the typewriter. He also invented the solar compass, a surveying tool used in the Michigan Survey, employed in regions that had an abundance of minerals, which would interfere with accurate readings when using ordinary instruments. While out surveying on September 19, 1844, in what is today Marquette County, Michigan, Burt discovered one of the largest iron ore deposits in the United States. His solar compass and adaptations of it became standard instruments for the government land survey in much of the western US, and were used until GPS was available in the late 20th century. A historical plaque commemorates William Austin Burt at Stony Creek, near his home in Mt. Vernon, Michigan.

He was awarded the John Scott Medal of The Franklin Institute in 1834.