Polygonal Barn may refer to:

(by state then town)

• Ben Colter Polygonal Barn, St. Marys Township, Adams County, Indiana, listed on the National Register of Historic Places (NRHP)
• Dyas Hexagonal Barn, Bellevue, Iowa, NRHP-listed
• Polygonal Barn, New Oregon Township, Cresco, Iowa, NRHP-listed
• W.J. Buck Polygonal Barn, Diagonal, Iowa, NRHP-listed
• McCoy Polygonal Barn, Hepburn, Iowa, NRHP-listed
• Polygonal Barn, Van Buren Township, Jackson County, Iowa, NRHP-listed
• Polygonal Barn, Lincoln Township, Johnson County, Iowa, NRHP-listed
• Thomas Reburn Polygonal Barn, New Albin, Iowa, NRHP-listed
• William Haner Polygonal Barn, Pisgah, Iowa, NRHP-listed
• Thomas Johnson Polygonal Barn, Wellman, Iowa, NRHP-listed
• Kuykendall Polygonal Barn, Romney, West Virginia, NRHP-listed

• Octagon Barn (disambiguation)
• Round Barn (disambiguation)