Helena Jaczek

In 2003, Jaczek ran as the Liberal candidate in the riding of Oak Ridges. Issues included tax rates and health care.[5] She lost to incumbent Frank Klees by 2,521 votes.[6] In 2007, Jaczek won the newly formed riding of Oak Ridges—Markham by 7,013 votes beating Conservative candidate Phil Bannon and New Democrat Janice Hagan. She was re-elected in the 2011, and 2014 elections. At the time, Oak Ridges-Markham was the most populous riding in the province until redistribution in 2018.

Jaczek was appointed as a Parliamentary assistant (PA) to the Minister of Health Promotion on October 30, 2007. On September 11, 2009 she was made PA to the Minister of Environment. In February 2013, Jaczek was appointed as PA to the Minister of Health and Long-Term Care.[7] From 2011 to 2014, she served as chair of the Liberal Caucus, under the premierships of both Dalton McGuinty and Kathleen Wynne. Jaczek was a member of several Standing Committees: Public Accounts, Social Policy, Government Agencies, Finance and Economic Affairs. During her time on the Standing Committee on General Government, she was Vice Chair.

Jaczek was also a member of the Select Committee on Mental Health and Addictions. This special Committee held public hearings around the province, visiting mental health and addictions facilities and several First Nations communities to better understand the Mental Health and Addictions program challenges facing Ontario. The Committee's work and recommendations were presented in the report, Navigating the Journey to Wellness.

Jaczek brought forward several Private Member’s Bills. In 2009, she proposed a private member's bill, Bill 117, that would have prohibited riders under the age of 15 from riding motorcycles.. In September 2010, she co-sponsored a private member's bill with PC and NDP MPPs to amend the Arthur Wishart Act (Franchise Disclosure)2000, to better protect perspective franchisees. In March 2012, Jaczek introduced a private member's bill, Bill 40, to proclaim March 26  Epilepsy Awareness Day. She also introduced a private member's resolution to encourage organ donations. In February 2013, she introduced Bill 16, "An Act to amend the Municipal Act, 2001 to provide that the head of council of The Regional Municipality of York must be elected." On June 6, 2013,the bill received the support of all three parties, but it .  died on the order paper because of the 2014 Ontario General Election. However, in November 2016, the government introduced legislation that included a provision to ensure the direct election of Chair and CEO of the Regional Municipality of York. This was subsequently overturned by the incoming PC government of Premier Doug Ford.

On June 24, 2014, she was appointed by Premier Kathleen Wynne as the Minister of Community and Social Services and was the Vice Chair of Health, Education and Social Policy Cabinet Committee.[8]

As a Cabinet Minister, Jaczek led the government's plan to reform social assistance, which includes overseeing Ontario's Basic Income Pilot as well as the establishment of the Income Security Reform Working Group who was tasked with developing ideas for a more holistic, client-centred approach to a broader income security. Jaczek has also overseen considerable reform in the developmental services sector, which includes the closing of all sheltered workshops in Ontario and has led the implementation of Ontario's Strategy to End Human Trafficking.

Jaczek was appointed Chair of Cabinet in addition to her role as Minister of Community and Social Services on January 17, 2018.

On February 26, 2018, she was appointed Minister of Health and Long-Term Care. During her time as Minister, the provincial government made an investment of $2.1 billion in mental health and addiction services.[9] This was the largest provincial investment in mental health and addictions in Canadian history. The purpose of the funding was  improving the quality of and access to community-based services, including the creation of 15 additional youth wellness hubs and more supportive housing.[10]

She lost re-election in the 2018 Ontario general election.

In June 2019, there was speculation that Jaczek might enter federal politics and run as a Liberal Party of Canada candidate in Markham—Stouffville in the 2019 Canadian federal election, against the incumbent Independent MP Jane Philpott. Philpott had previously been elected as the Liberal member but had been removed as a candidate following her expulsion from the Liberal caucus in the wake of the SNC-Lavalin affair. In July 2019, Jaczek announced that she would be seeking the Liberal Party nomination in the riding.[11] While it was speculated that two candidates splitting the Liberal vote would lead to a Conservative taking the riding, Jaczek won decisively with a larger margin of victory over the Conservative candidate than in the 2015 federal election. Philpott, as an independent candidate, came in third.

As Member of Parliament for Markham—Stouffville in the House of Commons, Jaczek serves as a member of the Standing Committee on Industry, Science, and Technology, and the Standing Committee on Transport, Infrastructure, and Communities. During the COVID-19 pandemic, Jaczek was invited to take part in the Standing Committee on Health. She also participated in virtual town halls to answer questions on the government response to the pandemic.

As part of the Standing Committee on Health, Jaczek used her expertise in medicine and public health to contribute to Canada’s response to COVID-19, within the country and globally. She advocated for funding transparency, greater safety on airlines and better public health standards in the agricultural sector.[12]