The Commercial Building is a historic skyscraper in central Dayton, Ohio, United States. Constructed in the early twentieth century, it played an important part in the development of the western portion of downtown Dayton, and it is one of the most prominent surviving examples of the work of one of the most significant architects in the city's history. Located at the edge of what was once one of the city's leading commercial complexes, it has been named a historic site.