Port Colborne is a city situated in the Niagara Region of Southern Ontario, Canada. It rests on the northern shore of Lake Erie at the southern terminus of the Welland Canal. This strategic location places it at the southern end of the Niagara Peninsula, serving as a key maritime and industrial hub within the region.

The original settlement, known as Gravelly Bay, dates from 1832 and was renamed after Sir John Colborne, Lieutenant Governor of Upper Canada. Growth focused around the canal's southern terminus after it reached Lake Erie in 1833. The town incorporated as a village in 1870, became a town in 1918, merged with Humberstone in 1952, and was reincorporated as a city in 1966.

The city features diverse communities including Bethel, Cedar Bay, and Lorraine. Historic Tennessee Avenue retains over 30 grand summer homes built by American tourists from the Southern states starting in 1888, showcasing late nineteenth-century Southern architecture. The area also includes the Clarence Street Bridge, one of only three remaining lift bridges on the canal, and Lock 8, which is among the world's longest canal locks.

Port Colborne hosts the annual Canal Days festival, featuring live music, antique car shows, and tall ships to honor the Welland Canal's history. The Port Colborne Historical and Marine Museum offers local archival research and historic artifacts. The community supports professional theatre at the Lighthouse Festival Theatre and amateur performances by the Port Colborne Operatic Society, drawing visitors with its cultural attractions.

The 2021 census recorded a population of 20,033 in 8,710 private dwellings. The economy relies on maritime commerce, agro-business operations like Casco Inc., and industrial employers such as Vale Canada Limited. Access is available via Buffalo-Niagara International Airport, approximately a forty-five-minute drive away, or through the Queen Elizabeth Way highway network.