Friends of Science (FoS) is a non-profit advocacy organization based in Calgary, Alberta, Canada. The organization rejects the established scientific consensus that humans are largely responsible for the currently observed global warming. Rather, they propose that "the Sun is the main direct and indirect driver of climate change," not human activity. They work to cast doubt on anthropogenic climate change, communicate this doubt to the public, and engage in political debates to defend the hegemony of Canada's fossil fuel industry. The society was founded in 2002 and launched its website in October of that year. They are largely funded by the fossil fuel industry.

Madhav Khandekar, Chris de Freitas, Tim Patterson and Sallie Baliunas act or acted as advisers to the Friends of Science with their work cited in Friends' publications. Douglas Leahey has been president since December, 2009.

In the late 1990s the Calgary-based Canadian Society of Petroleum Geologists, a group modeled on the American Association of Petroleum Geologists, invited Chris de Freitas, from The University of Auckland, a critic of the Intergovernmental Panel on Climate Change (IPCC), as guest speaker. Following these talks in which de Frietas was "very critical of what was being said about the role of carbon dioxide in global warming, ...[w]e all left the luncheon speeches all shaking our heads that this silliness was going on." After the Canadian government signed the Kyoto Protocol, Eric Loughead, former editor of the Canadian Society of Petroleum Geologists Bulletin and his fellow members of the Canadian Society of Petroleum Geologists responded by creating the Friends of Science Society, who held its first meeting in the curling lounge of the Glencoe Club in Calgary in 2002.

The first board of directors in 2002 included oil industry geologist and member of the Canadian Society of Petroleum Geologists, Arthur M. Patterson, as President; Gordon C. Wells, as Vice-President; Charles Simpson as Secretary and H. Graham Donoghue as Treasurer. Founding members of the Friends of Science, Arthur M. Patterson, Albert Jacobs, and David Barss (Hons. Geol. published the Canadian Society of Petroleum Geologists (CSPG) position on global climate change science in January 2003 in which they cite an article by Chris de Freitas entitled "Are Observed Changes in the Concentration of Carbon Dioxide in the Atmosphere Really Dangerous?"

In 2002, as faculty member of the University of Calgary, political scientist Barry Cooper, set up the Science Education Fund which could accept donations through the Calgary Foundation. The 57-year-old charity, Calgary Foundation administers charitable giving in the Calgary area and had "a policy of guarding donors' identities." Albert Jacobs, a geologist and retired oil explorations manager, who attended the first meeting held in the curling lounge of Calgary's Glencoe Club back in 2002, described how donations from industry donors were passed on to the Science Education Fund set up by Barry Cooper, which in turn supported the activities of the Friends of Science.

In 2004 Talisman Energy, a Calgary-based, global oil and gas exploration and production company, one of Canada's largest independent oil and gas companies, donated $175,000 to fund a University of Calgary-based "public relations project designed to cast doubt on scientific evidence linking human activity to global warming." Journalist Mike De Souza published the list of significant donations to the Friends of Science which had been received by the press, in an article published in the Vancouver Sun in 2011. Sydney Kahanoff, a Calgary oil and gas executive and philanthropist donated $50,000 through his Kahanoff Foundation, a charity he established in 1979. Murphy Oil matched one of its employees $1,050 donations. Douglas Leahey defended the donations to the Friends of Science from the then CEO of Talisman Energy, James Buckee, who shared the Friends' views on climate change.

On their original web page, dated 2002, the Friends recommended several key documents explaining their standpoint, including testimonies by George C. Marshall Institute former board members, Richard S. Lindzen and Sallie Baliunas. Richard S. Lindzen's testimony before the Senate Environment and Public Works Committee on 2 May 2001. Lindzen, a former member of the UN's Intergovernmental Panel on Climate Change became one of the most well-known climate "skeptic" scientists. A prolific writer, he has been criticizing the IPCC since the early 1990s. Noted deniers Sallie Baliunas was also a paid consultant of the George C. Marshall Institute.

The Friends' short recommended reading list also included the anti-Kyoto testimony provided by Harvard-Smithsonian astrophysicist, Sallie Baliunas, well-known denier, to the Senate Committee on Environment and Public Works. Baliunas claimed that, "[p]roposals like the Kyoto agreement to sharply cut greenhouse gas emissions are estimated in most economic studies to have enormous economic, social and environmental costs. The cost estimates for the U.S. alone amount to $100 billion to $400 billion per year. Those costs would fall disproportionately on America's and the world's elderly and poor." MacRae, an engineer, investment banker and environmentalist warned of economic fall-out and inaccurate science of the Kyoto accord. The Friends recommended Wildavaky's 1995 publication in which he claimed that "an all-powerful environmental community" overstated risks in everyday life.