Environmental issues in Canada include impacts of climate change, air and water pollution, mining, logging, and the degradation of natural habitats. As one of the world's significant emitters of greenhouse gasses, Canada has the potential to make contributions to curbing climate change with its environmental policies and conservation efforts.

Climate change is greatly impacting Canada's environment and landscapes. Extreme weather has become more frequent and severe because of the continued release of greenhouse gases into the atmosphere. The number of climate change–related events, such as the 2021 British Columbia Floods and an increasing number of forest fires, has become an increasing concern over time. Canada's annual average temperature over land warmed by 1.7 °C (3.1 °F) between 1948 and 2016. The rate of warming is highest in Canada's north, the Prairies, and northern British Columbia. The country's precipitation has increased in recent years and wildfires expanded from seasonal events to year-round threats.

As of 2022^[update], Canada was the world's 11th highest emitter of carbon dioxide (CO₂) and as of 2021 the 7th highest emitter of greenhouse gases. Canada has a long history of producing industrial emissions going back to the late 19th century. In 2022 transport, oil and gas extraction, and fugitive emissions together emitted 82% of the country's total emissions. From 1990 to 2022, GHG emissions from conventional oil production increased by 24%, those from multi-stage fracturing techniques increased by 56%, and emissions from oil sands production increased by 467%. This has led to criticism against Canada for committing to reducing greenhouse emissions while supporting its oil and gas industry.

Canada committed to reducing its greenhouse gas (GHG) emissions by 30% below 2005 levels by 2030 under the Paris Agreement. In July 2021, Canada enhanced the Paris Agreement plans with a new goal of reducing emissions by 40–45% below 2005 levels by 2030, enacting the Canadian Net-Zero Emissions Accountability Act. In 2019, the House of Commons voted to declare a national climate emergency in Canada. Several climate change mitigation policies have been implemented in the country, such as carbon pricing, emissions trading and climate change funding programs.

Scientists across the world have already started to notice massive reductions in Canada's Arctic sea ice cover, particularly during the summertime. The shrinking of this ice results in the disruption of the ocean circulation, and changes in climate and weather around the world. The 2019 Canada's Changing Climate Report, written by scientists from institutions around the globe, states that the impacts of climate change on Atlantic Canada will be very diverse. One impact is that the sea ice will become thinner and will also form for much shorter periods of the year. And with less sea ice than the region usually gets now, wave seasons will become more intense. Atlantic Canada will see a relative rise in sea levels everywhere - a rise which is estimated to be 75 to 100-cm by the year 2100. Scientists also predict that even if emissions decrease, a 20-cm rise is expected to take place during the course of the next 20 to 30 years. NASA studies have also found that a major ocean current in the Arctic has become faster and more turbulent due to the rapid ice melt, disrupting the delicate balance of the Arctic environment with an influx of freshwater. As the ocean warms and subtropical waters move north, the ocean will become warmer and saltier, and since warmer water holds less oxygen than cooler water, marine ecosystems can suffer and become less sustainable because of this lower oxygen level. In the journal, Science, which was published in March 2019, it explains that warmer waters could actually increase fish stocks in certain regions, like the halibut found off the coast of Newfoundland and Greenland but other species such as the Atlantic Cod and albacore tuna might not be able to cope with the conditions so well.

Wildfires are a major concern in Canada, with an average of over 7,000 wildfires occurring each year in Canada. Since 1990, these fires across Canada have consumed approximately an average of 2.5 million hectares a year. Wildfires are a recurrent natural disaster in Canada, escalating due to climate change and other human-induced factors. The situation has worsened over the years, with 2023 marking a particularly devastating wildfire season. The wildfires led to massive evacuations, with tens of thousands of people displaced from their homes. In British Columbia, about 35,000 individuals were under evacuation orders, and over 30,000 were on evacuation alert due to the intensifying fires. The wildfires also caused substantial property and infrastructure damage, destroying nearly 200 homes and structures in Kelowna, BC. The Canadian federal government, along with provincial authorities, initiated several measures to combat the fires and mitigate their impacts. This included deploying the military to affected regions, imposing travel restrictions, and soliciting international assistance.

The environmental issue of pipelines in Canada is a complex and multi-faceted concern, encompassing potential impacts on both natural ecosystems and human communities. Public opinion in Canada reflects a significant opposition towards government financial involvement in oil pipelines. Many Canadians opposed a multibillion-dollar writedown on the Trans Mountain oil pipeline by the federal government. Additionally, Canadian governments have provided over CAD 23 billion to oil and gas pipelines in the last few years. This financial support was aimed at boosting the economy, but critics often argue it undermines Canada's green recovery efforts by potentially increasing carbon emissions. Economically, the new pipeline still serves as a strong case, helping open up newer markets for Canadian producers.

The Canadian Energy Regulator controls about 10% (73,000 km) of the pipelines in Canada, their Pipeline Safety Act, as a regulatory response, aims to mitigate several risks by enhancing pipeline operating safety and environmental protection measures. From a technical perspective, corrosion, construction defects, and cracking are generally the most commonly identified leading causes of pipeline leaks in Canada, emphasizing the need for robust maintenance and safety protocols. Additionally, there are measures in place for preventing and responding to marine oil spills, including using satellite technology for detection and surveillance and advancing science to improve cleanup technologies.