One of 17 Canadian port authorities created by the federal government, Hamilton-Oshawa derives its mandate from the Canada Marine Act.

[8] A 2010 study by Martin and Associates revealed that cargo transiting the Port of Hamilton is connected to $6 billion in economic activity and 38,000 jobs in the province of Ontario.

In order to accommodate the huge ore and coal ships which now had direct access to Harbour waters, the Steel Company of Canada and the Hamilton By-Product Coke Ovens constructed larger docks.

The result: between 1929 and 1934 total tonnage in the harbour doubled from one to two million tonnes annually, making Hamilton the fourth-busiest port in the country, behind Montreal, Vancouver and Toronto.

Cargo tonnage after the first year of Seaway operation was higher in Hamilton than at any other Canadian or American Port on the Great Lakes.

From 2006 to 2018 the share of tonnage related to the steel industry steadily declined but began stabilizing around 2013 in the 6 to 7 million tonne range.

Partial recovery has occurred in the breakbulk category with relatively consistent annual increases from 2009 to 2018 but liquid bulk tonnage (chemicals, fuels, etc.)

From 2010 to at least 2012 Blount Small Ship Adventures made multiple visits annually on their cruise between New York City and Toronto with the MV Grand Mariner.

[29][30][31] In 2017 Hamilton was also the 7th busiest Canadian port authority behind Vancouver, Montreal, Saint John, Quebec City, Prince Rupert and Sept-Iles.

It imports/exports large project cargo components such as windmill blades and handles salt, agri-food commodities, fertilizers, fuels and assorted inputs and finished product for the steel industry.

[38] As of 2019, regular short sea container shipping between Hamilton and eastern Canadian, deep water ports has not been realized.

However, most major ports in the Great Lakes-St. Lawrence Seaway system continue to advance the idea of short sea shipping generally, through initiatives such as the Highway H2O [39] marketing campaign, as most Great Lakes ports see potential for an increased, less commodity/industry specific role in regional logistics for marine traffic.

As a result, it is not uncommon for port authority's to come into conflict with municipal political leadership whose interests are more local in nature.

Ontario's Minister of Environment, Jeff Yurek, stated "there is simply no evidence to give reason to believe [the port merger] can possibly meet [the federal government's] stated goals of strengthening Ontario's supply chain and improving port efficiencies and planning in the region.

"[44] By contrast Hamilton Mayor Fred Eisenberger said "the combination of the two port authorities would allow the new entity to boost growth and improve southern Ontario's access to global markets.

The port authority manages 620 acres of waterfront industrial property in Hamilton; however, it is running out of land to advance its financial and economic mandate.

[47] In October 2013 former President of the Hamilton Port Authority Bruce Wood publicly mused that if US Steel (Stelco) was going to close its last steel mill in Hamilton it was an opportunity for the port authority to buy the 328 hectares (810 acres) Stelco occupies and repurpose it to create new jobs on the brownfields.

On November 15, 2019, the port authority began the purchase of a site adjacent to its property which once housed a fuel depot operated by Petrocor.

[55] As a result of some of the negative byproducts the city's industrial history and a desire to cleanup the local environment and reputation there was significant opposition to a port leaseholder's proposal to build a waste gasification facility on Pier 15.

The result called into question the short-term financial viability of the port as they were found to have almost 6 million dollars in total liabilities.

[58] There has also been long-standing local opposition to the port, or at least its economic development mandate, due to its proximity to neighbouring Second Marsh and position between two conservation areas.

The Hamilton Port Authority had initially agreed to grant public access in 2007 but for security reasons later changed their position.

[63] In order to address the issue of community waterfront access HOPA is currently in the midst of a public engagement process for Fisherman's Wharf in Hamilton.

Scheduled to be completed in 2022 the 7 hectare containment facility will be converted to port uses and could lead to Hamilton Harbour being removed as an Area of Concern by the International Joint Commission.