The daughter of former Alberta NDP leader Grant Notley, she was a lawyer before entering politics; she focused on labour law, with a specialty in workers' compensation advocacy and workplace health and safety issues.

[3] In the 2019 provincial election, the NDP government was defeated by the United Conservative Party, making Notley the Opposition leader.

In the 2023 provincial election, the NDP made large gains but failed to form government, with Notley continuing as Opposition leader.

[17] Alongside her own family background, Notley has also cited her high school social studies teacher Jim Clevette as having made a lasting impact when it comes to her interest in politics.

[19] After attending a large party she received a call at four in the morning from Tom Sigurdson, her father's executive assistant, stating that there had been a plane crash and that she should return home.

[9] While at Osgoode Hall she became active in the 1989 federal NDP leadership convention where she endorsed second-place finisher and former BC premier Dave Barrett.

[19] In August 1997, she married Lou Arab, a communications representative for the Canadian Union of Public Employees (CUPE) and a campaign strategist for the party.

[16] After law school, Notley articled for Edmonton labour lawyer Bob Blakely, and went on to work for the Alberta Union of Provincial Employees representing members with Workers' Compensation cases.

[19] In this role, she was part of the team that first expanded the application of BC's family relations laws to same sex couples, several years before the Government of Canada took similar initiatives.

Notley acted as a representative of the provincial labour movement in the negotiation and drafting of new workplace health and safety standards.

[29] In addition to serving as party leader, Notley was critic for Health, International and Intergovernmental Relations, Status of Women, Justice, and Executive Council.

[3] With the Official Opposition Wildrose Party reeling from a series of floor crossings and mass defections, most pundits and commentators felt that the PCs had a good shot at winning their thirteenth consecutive majority in the Legislature.

[33][34] By the middle of the campaign, however, pollsters began predicting a three-way race between the Progressive Conservatives, the Alberta NDP, and the Wildrose Party.

[35] Notley had managed to capitalize on the unpopularity of the PCs' budget, stating that she would instead raise corporate taxes and rollback fees and cuts.

[37] Jim Prentice also came under fire for saying "I know math is difficult" to Notley, in reference to the embarrassing miscalculation in the proposed NDP budget released two days prior,[38] a remark which was widely seen as sexist and patronizing.

[41] She also met with outgoing Premier Jim Prentice that same day, in addition to extending the deadline for the province's school boards to submit their budgets, her first major deviation from the previous Progressive Conservative government's financial commitments as Premier-designate.

[49] That same day Notley also announced the creation of a seventeen-member all-party committee tasked to look into ways to improve government accountability in areas such as whistleblower protection, electioneering, and conflicts of interest.

On December 8, 2015, Notley tweeted out her support of Prime Minister Justin Trudeau's announcement that a national inquiry into missing and murdered indigenous women and girls would be immediately launched.

The budget of 2017 included $100 million to upgrade the provincial and federal waterworks facilities that provide drinkable water for Albertan First Nations Communities.

[53] On November 22, 2015, Notley unveiled Alberta's updated climate change strategy, in time for the COP 21 conference in Paris.

The plan also included a phase-out of coal-fired electricity by 2030, a 10-year goal to halve methane emissions, as well as incentives for renewable energy.

In 2018, the NDP proposed legislature Bill 9 to enforce 50 metre buffer zones around abortion clinics in Alberta to ban harassment by pro-life activists against users and personnel of these facilities.

[59] The proposed Bill 24 designed to protect LGBTQ rights will uphold anonymity among members of gay–straight alliance (GSA) clubs in public schools.

[65] The curtailments were meant to minimize lost revenue due to oil being sold at a lower market value as a bottleneck in transportation.

The Alberta government rarely utilized this power, the last time was during the National Energy Program to limit federal revenues.

[66] Curtailments took effect in January 2019, under the Oil and Gas Conservation Act with the Alberta Energy Regulator monitoring the program.

As stated by the Edmonton Sun, "The statistics show that from 2003 to 2015, Alberta Sheriffs recorded 55 security incidents involving six premiers.

While the NDP retained all but one of their seats in Edmonton, significant losses in Calgary and rural Alberta reduced them to Official Opposition status.

[75] Initially, the Kenney government enjoyed substantial support among Albertans, but his approval rating started to decline with the onset of the COVID-19 pandemic in Alberta.

[76][77] During the campaign, the NDP received endorsements from former Progressive Conservative ministers, former Calgary mayor Naheed Nenshi, and former Liberal Party of Alberta leader David Swann.