There have been two lighthouses and two range lights at Port Colborne harbour during the fourth Welland Canal era.

The main, or inner, lighthouse was built in 1903 on the west breakwater, and is still there today. In the 1920s, in order to give added protection to Port Colborne harbour, a major new extension was added to the west breakwater. To guide ships around the extension, a second lighthouse was built on its southern end: the outer lighthouse. As part of the construction project, a tunnel was created from the inner lighthouse to the outer lighthouse to give the lightkeeper protection in rough weather. The breakwater extension and lighthouse were both completed in 1927.

The range light located near Fares St. and Lake Rd. was used until it was torn down in 1927. Another eastern range light was erected c. 1903 on the western end of the east breakwater.

During the fourth canal era, major technological upgrades have transformed the lighthouses and navigational safety. For example, in 1927, the first electric 200-watt double filament bulb was installed, and oil-fuelled generators became the new power source. In 1942, a radio beacon and distance finding station was installed, and in 1954, new submarine power cables were laid to the breakwall to provide electricity to power the lighthouses.

Although these advancements created an even safer entrance to the harbour for shipping and often made the lightkeeper's job easier, eventually they led to full automation in 1986. This eliminated the need for a lightkeeper at Port Colborne. In 1990, the lightkeeper's dwelling was torn down.

The advent of even more advanced navigational technology, especially GPS (Global Positioning System), has reduced the need for lighthouses. As a result, in 2010, the Canadian government declared the Port Colborne lighthouses, and many others, as surplus.

Soon after, interested Port Colborne residents formed a non-profit organization, the “Friends of the Port Colborne Lighthouses” to bring awareness and advocate for the preservation of these historic buildings.