Daniel Day Wiley (August 10, 1837 – January 25, 1893) was a Union Army officer during the American Civil War. Wiley was born in Readsboro, Vermont on August 10, 1837. He was a merchant before the Civil War. Wiley was a merchant and United States Customs Service agent after he was mustered out. Daniel Day Wiley died January 25, 1893 at Sudbury Centre, Massachusetts. He was interred at Greenlawn Cemetery, Baldwinville, Massachusetts.