Burlington Bay, also known as Hamilton Harbour, is a branch of Lake Ontario bounded on the northwest by the City of Burlington, on the south by the City of Hamilton, and on the east by Hamilton Beach (south of the Skyway Bridge ) and Burlington Beach (north of the channel). It is joined to Cootes Paradise by a narrow channel formerly excavated for the Desjardins Canal. Within Hamilton itself, it is referred to as Hamilton Harbour, the Harbour and the Bay, but never Burlington Bay.

Access to the bay was important for the early water transportation and industrial development of the area, including Dundas, Ontario which had an early but ultimately unrealized lead over both Burlington (Brant's Block) and Hamilton. However, it was roughly treated by its littoral residents.

Constant infilling, particularly in the North End of Hamilton, damaged fresh water streams and the wildlife it supported. Channel dredging tended to stir up natural and unnatural sediments, further disrupting the ecological balance in the area. Chemical, industrial and thermal pollution, especially as a byproduct of the burgeoning steel industry after the 1890s, continued to degrade the environment.

The need for remedial action was widely recognized by the 1970s, including by the International Joint Commission governing water usage in the Great Lakes basin. By the 1980s, greater awareness, improved pollution control and an economic downturn which reduced heavy industrial activity, biologically active pollution in the bay was dramatically decreased. In the 1990s, efforts at beautification and ecological control were well underway. These measures included sealing the Lax Lands, contaminated with heavy metals and other pollutants, under a cap of clay and landscaping Bayfront (or Pier 4) Park and keeping Asian carp from entering Cootes Paradise. The visible and measurable improvement in water quality in Burlington Bay was showcased by the very public swim of Sheila Copps, a local MP and federal cabinet minister.