William Fisher Polygonal Barn

William Fisher Polygonal Barn, also known as the Fisher-Dykes Barn, is a historic 10-sided barn located in Sugar Creek Township, Montgomery County, Indiana. It was built in 1914, and is a two-story, balloon frame structure on a concrete foundation. Two of the 10 sides are 28 feet wide, while the 8 remaining sides are 16 feet wide. The barn is topped by a sectional two-pitched gambrel roof with flared eaves. Atop the roof is a six-sided cupola.

It was listed on the National Register of Historic Places in 1993.