Commercial Street is a downtown street in the Old Port of Portland, Maine, United States. It is part of U.S. Route 1A. It became the Old Port's waterfront in the early 20th century, replacing Fore Street, after land was reclaimed from the waters of Casco Bay and the Fore River.In 2008, it was named one of the ten best streets in the United States by the American Planning Association. Built upon old piers in the 1850s, fill was pushed into Casco Bay to accommodate the growing railroad and warehousing needs of the port's working waterfront. In the 1970s and 1980s, much of the economic activity on the street was hurt and many of the properties on the street were sold off for non-marine development, including the building of condominiums. In 1987, Portland voters, led by local fisherman based on Commercial Street, halted all non-marine development along the street and adjacent docks. Marine development around Commercial Street returned in the 1990s and 2000s (decade) alongside other economic development, including tourism-related industries.The Maine State Pier, a deepwater marine facility and outdoor music venue, is located at the intersection of Commercial Street and Franklin Street. The Portland Star Match Factory, located at 65-89 West Commercial Street near the West End.
The street, which was originally known as Thames Street, becomes West Commercial Street from beneath the Casco Bay Bridge heading west. Thames Street still exists from India Street heading northeast, eventually merging into footpaths beneath the Eastern Promenade.