[5] CGI Inc. was founded as an IT consulting company on June 15, 1976, in Quebec City, Québec, by Serge Godin.

Starting with one client,[8] as the company grew in size the co-founders moved to Montreal,[7] and by the end of their first year they had generated $138,000 in revenue.

[15] As of late 2004, CGI was the world's eighth largest independent provider of information technology services.

[25] Continuing to work in the financial sector, CGI was rated as a "major contender" by Everest Group in a 2013 PEAK Matrix study looking at IT outsourcing capital markets.

[7][29][30][31][32] In 2014, CGI had contracts with federal businesses such as Defense Information Services Agency, visa processing in China, and the Coast Guard and Department of Homeland Security.

[33] In 2014, The Globe and Mail reported that CGI was operating ten security centers, from which 1,400 CGI employees monitor "data traffic for an undisclosed number of customers" that include the Canadian Payments Association, the National Bank of Canada, and about forty Canadian government departments.

[34] By 2014, CGI had been working with the European space industry for years, and had developed software that helps support the missions of over 200 individual satellites.

[41] In 2016, CGI had contracts with the British Columbia Ministry of Health,[42] the U.S. Navy to work on their NAVSUP Business Systems Center,[43] the Swedish social insurance agency,[44] Sears Canada,[45] and the Queensland government,[46] among others.

[48] In 2019, The Wall Street Journal indicated CGI was part of the Chinese APT10 group's Operation Cloud Hopper hack, which exposed companies' data from 2013 to 2017.

[49] CGI originally stood for "Conseillers en gestion et informatique" (translated to English: "Consultants on management and information systems").

[56] Originally CGI focused its products and services on IT consulting, and the company later branched into outsourcing, software development, and systems integration, among other industries.

As reported by Vanity Fair, CGI's work on the site frustrated government officials due to missed deadlines, with the CMS's chief operating officer stating, "If we could fire them, we would.

[70] Additionally, Reuters documented the U.S. government's decision to part ways with CGI after the site "failed to work when it launched in October" and experienced ongoing issues, further igniting political debates.

Furthermore, the contract was terminated, and a group of other IT companies successfully replicated the registry, rendering CGI's project obsolete.

Consequently, due to contract stipulations requiring payment only upon satisfactory delivery, the province refused to pay CGI.

However, the website's launch on Oct. 1 encountered severe technical issues, causing user frustrations due to site crashes and inaccessibility.

Senate President Donna Mercado Kim had previously cautioned against employing CGI Group, referencing their involvement with the problematic Hawaii state tax department website.

The adjusted agreement appeared more beneficial to CGI than to Hawaii, according to House Finance Chairman Marcus Oshiro.

The audit was influenced by claims from a former tax research officer, Tu Duc Pham, who suggested that the revised agreement with CGI unduly favored the company.

Overall, CGI has received contracts amounting to approximately $90 million from Hawaii's Tax and Health departments since 1999, with a notable portion being awarded without competitive bidding.