Marion's Piazza is a pizzeria chain based in Dayton, Ohio. Established in 1965 by Marion Glass, the company operates nine restaurants throughout the greater Dayton area. Marion's son, Roger Glass, took over as CEO after Marion's death in 2006 and continued to manage the company until his passing in August of 2022. The pizzeria produces what it calls "Dayton-style pizza". In 2017, it was recognized by the trade publication Pizza Today, as the number one independent pizza chain based on sales. Roger Glass, the CEO, noted that the company won the award four of the last five years.