[11] Stefanson was first elected to the Manitoba legislature in a 2000 by-election, replacing former Progressive Conservative Premier Gary Filmon in the south Winnipeg riding of Tuxedo.

[2] Stefanson was first elected to the Manitoba legislature in a 2000 by-election, replacing former Progressive Conservative Premier Gary Filmon in the south Winnipeg riding of Tuxedo.

Stefanson defeated Liberal Rochelle Zimberg by 2692 votes to 1586; Iona Starr, representing the governing New Democratic Party (NDP), finished third.

[12] As MLA for Tuxedo, Stefanson has been an advocate for Special Olympics Manitoba, an organization dedicated to enriching the lives of people with intellectual disabilities through sport.

[21] As Premier in 2022, Stefanson announced $2 million to support a $15-million capital campaign to build the new Toba Centre for Children & Youth at 710 Assiniboine Park Drive.

[23] Stefanson was sworn in as Minister of Justice and Attorney General in a ceremony at the Canadian Museum of Human Rights in 2016, becoming only the second woman to hold that position since 1871.

[32] University of Ottawa law professor Allan Rock estimated the legislation would produce an 87 percent reduction in preliminary inquiries and help reduce court delay significantly.

[33] In a statement regarding the federal, provincial and territorial Justice Ministers meeting in April 2017, Stefanson expressed her support for mandatory minimum sentences for certain criminal offences.

[46] Stefanson defended the home grow prohibition as a means of keeping cannabis away from children and preventing diversion of supply into the black market.

[44] The Canadian Association of Chiefs of Police had joined Stefanson and other Justice Ministers in calling for a national prohibition of home cultivation in April 2017.

She was joined by the Minister of Health, Seniors and Active Living who announced a provincial prohibition on smoking cannabis in outdoor public places.

[58] Stefanson credited the government's emphasis on preventative measures as helping at-risk families avoid contact with the child welfare system.

In January 2020, Stefanson announced that the province would end the controversial practice of birth alerts, where CFS agencies warn hospitals about the history of a pregnant mother considered "high risk.

[64] Manitoba Keewatinowi Okimakanak Grand Chief Garrison Settee expressed excitement at the news, telling media "we applaud the province for listening to us.

[65] Stefanson had previously invested $400,000 to launch Granny's House, a two-story home in North Point Douglas that provides short-term respite for parents otherwise at-risk of CFS contact.

[69] In July 2020, Stefanson announced a $31 million investment in repairs to Manitoba Housing properties, estimated to make over 800 otherwise vacant units ready for new tenants.

[77] Stefanson also announced a partnership with telecommunications firm TELUS to support children in CFS, with the donating 120 tablets with data plans to the province.

[86] The province worked with community organizations to 2,500 families with packages of healthy foods, including recipes and learning activities developed by the Child Nutrition Council of Manitoba.

As Premier, Stefanson later announced $15 million to implement the Stevenson review recommendations, which included enhancing infection prevention and control, hiring 200 full-time housekeeping staff, and improving information technology to better support patient care.

[109] On September 24, 2021, her campaign published an endorsement letter signed by seven prominent businesspeople who expressed concerns about the anti-vaccine sentiments of her opponent, Shelly Glover.

[118] Stefanson is credited with dramatically improving relationships with other levels of government, which federal officials and Winnipeg Mayor Brian Bowman have remarked to media.

"[124] Loren Remillard, president and CEO of the Winnipeg Chamber of Commerce, praised the speech and said that it demonstrated that Stefanson's priorities were aligned with those of the business community.

[139] Stefanson later removed Tory MLA Josh Guenter from his role as Legislative Assistant to the Minister of Health for his continued disagreement with the government over COVID-19 vaccine mandates.

[140] Stefanson's Minister of Health announced the establishment of a Diagnostic and Surgical Recovery Task Force on December 8, 2021, to address the backlogs created by the COVID-19 pandemic response.

[142] The Budget, which was branded Recover Together, focused on five priorities – strengthening health care, making life more affordable, building the economy, investing in communities, and protecting the environment.

[145] The 2022 Budget Speech stated that cumulative tax changes since the Progressive Conservatives formed government in 2016 put $2,400 "back in the pockets" of the average Manitoban.

[150] On August 31, 2022, Stefanson announced a Family Affordability Package that included $87 million in measures to offset the rising cost of living for Manitobans.

Moreover, low-income seniors with less than $40,000 in family income who claimed an Education Property Tax Credit in 2021 would receive a $300 cheque to help with rising costs.

[176] Despite several phone calls and emails of concern over the closure,[177] enrolment in the remote learning centre was shown to have decreased by 85% since its launch in 2021—serving a student population of 1,050 in the 2020/21 school year, to near 200 by 2023.

In April 2024, she announced that she would resign from her seat and retire from politics,[180] triggering the 2024 Tuxedo by-election, which was won by the NDP, the first time the PC did not win the constituency since its creation in 1981.