20 Second Quarter Report 21 Creating communities through engineering improve quality of life through access to clean and design is our business. But our passion water, sustainable energy, conservation, and Sage Grouse Survey Elko, Nevada, USA is designing a sustainable future. ecosystem restoration. We are proud to be one of the top-ranked engineering and design Our approach to sustainability is ingrained in firms in the world. We further strengthened our DNA. You see this in the way we operate our position with several industry-leading our business, the way we put our people environmental, sustainability, and governance first, and in our commitment to design with rankings. To learn more about sustainability community in mind. Around the world, we at Stantec, including our pledge to achieving are working with clients and communities carbon neutrality and operational net zero, visit to build resilience, reduce emissions, and Stantec.com/Sustainability. Table of Contents MANAGEMENT’S DISCUSSION AND ANALYSIS Business Model and Strategic Plan M-1 Business Update – COVID-19 Pandemic M-2 Q2 2021 Financial Highlights M-3 Financial Targets – Revised M-7 Outlook M-7 Financial Performance M-9 Summary of Quarterly Results M-14 Statements of Financial Position M-16 Liquidity and Capital Resources M-17 Other M-19 Critical Accounting Estimates, Developments, and Measures M-20 Controls and Procedures M-21 Risk Factors M-22 Subsequent Event M-22 Caution Regarding Forward-Looking Statements M-22 UNAUDITED INTERIM CONDENSED CONSOLIDATED FINANCIAL STATEMENTS Consolidated Statements of Financial Position F-1 Consolidated Statements of Income F-2 Consolidated Statements of Comprehensive Income F-3 Consolidated Statements of Shareholders’ Equity F-4 Consolidated Statements of Cash Flows F-5 Notes to the Unaudited Interim Condensed Consolidated Financial Statements F-6 Management’s Discussion and Analysis August 4, 2021 This discussion and analysis of Stantec Inc.’s (Stantec or the Company) operations, financial position, and cash flows for the quarter and the two quarters ended June 30, 2021, dated August 4, 2021, should be read in conjunction with the Company’s unaudited interim condensed consolidated financial statements and related notes for the quarter and the two quarters ended June 30, 2021, and the Management’s Discussion and Analysis (MD&A) and audited consolidated financial statements and related notes included in our 2020 Annual Report filed on February 24, 2021. Our unaudited interim consolidated financial statements and related notes for the quarter and the two quarters ended June 30, 2021, are prepared in accordance with International Financial Reporting Standards (IFRS) as issued by the International Accounting Standards Board (IASB). We continue to use the same accounting policies and methods as those used in 2020, except for applying the indirect method to the consolidated statements of cash flows, a change from the direct method previously applied. Amendments to accounting standards disclosed in our December 31, 2020, audited consolidated financial statements (incorporated here by reference) did not have an impact on the Company’s consolidated financial statements or accounting policies for the quarter ended June 30, 2021. All amounts shown in this report are in Canadian dollars unless otherwise indicated. Additional information regarding our Company, including our Annual Information Form, is available on SEDAR at sedar.com and on EDGAR at sec.gov. Such additional information is not incorporated here by reference, unless otherwise specified, and should not be deemed to be part of this MD&A. Stantec trades on the TSX and the NYSE under the symbol STN. Visit us at stantec.com or find us on social media. Business Model and Strategic Plan Stantec is a global leader in sustainable design and engineering with 22,000 employees that operate out of 350 locations around the world. We design with community in mind and are well positioned to help clients around the world address the impacts of climate change, urbanization, emerging macroeconomic drivers, and technology shifts. We have strong expertise across the buildings, energy and resources, environmental services, infrastructure, and water sectors. Key components of our business model are geographic diversification; service diversification; focus on the higher-margin, lower-risk design phase of buildings, energy, and infrastructure projects; and providing professional services in all phases of the project life cycle. Our vision is to be a top 10 global design firm that maximizes long-term, sustainable value. We aim to grow and diversify sustainably for the benefit of our clients, employees, and shareholders. We will do this through a client- centric framework with four value creators: Excellence, Innovation, People, and Growth. Please see pages M-1 to M-5 of Stantec’s 2020 Annual Report for further details on our business model and strategic plan. Management’s Discussion and Analysis June 30, 2021 M-1 Stantec Inc. Strategic Acquisitions Completed in 2021 and 2020 Following is a list of acquisitions that contributed to revenue growth in our reportable segments and business operating units: BUSINESS OPERATING UNITS REPORTABLE Date Primary # of Energy & Environmental SEGMENTS Acquired Location Employees Buildings Resources Services Infrastructure Water Canada Teshmont October Winnipeg, 63 ● Consultants LP 2020 Manitoba (Teshmont) United States Wenck December Minneapolis, 300 ● 2020 Minnesota Global AGEL adviseurs December Oosterhout, 75 ● (AGEL) 2020 Netherlands GTA Consultants March Melbourne, 135 ● (GTA) 2021 Australia Engenium May Perth, 170 ● 2021 Australia Business Update – COVID-19 Pandemic Now into the second year of the pandemic, we have acclimatized to the new norm and new ways of working with our clients and with each other. As vaccines are rolled out, there is growing optimism that the increased protection offered by vaccines will gradually decrease the pandemic restrictions. Efforts are now in place to transition to the post- pandemic working environment. The majority of our offices are now open across North America and internationally, and staff are in the process of transitioning back to the offices following local office re-entry plans and protocols. As demonstrated by our performance in 2020 and the first two quarters of 2021 the ongoing pandemic is not impeding our growth or financial aspirations. We continue to see emerging opportunities within the sectors we serve as certain jurisdictions begin introducing or accelerate infrastructure and other stimulus programs – and we remain well- positioned to capitalize on them. Management’s Discussion and Analysis June 30, 2021 M-2 Stantec Inc. Q2 2021 Financial Highlights For the quarter ended For the two quarters ended June 30, June 30, 2021 2020 2021 2020 (In millions of Canadian dollars, except per share % of Net % of Net % of Net % of Net amounts and percentages) $ Revenue $ Revenue $ Revenue $ Revenue Gross revenue 1,134.0 124.8% 1,205.6 126.8% 2,223.2 124.4% 2,426.1 127.3% Net revenue 908.3 100.0% 951.1 100.0% 1,787.0 100.0% 1,906.3 100.0% Direct payroll costs 425.0 46.8% 461.4 48.5% 837.3 46.9% 909.9 47.7% Gross margin 483.3 53.2% 489.7 51.5% 949.7 53.1% 996.4 52.3% Administrative and marketing expenses 341.3 37.6% 344.0 36.2% 682.8 38.2% 711.3 37.3% Other (4.1) (0.5%) (1.2) (0.1%) (8.3) (0.5%) 9.9 0.6% EBITDA from continuing operations (note) 146.1 16.1% 146.9 15.4% 275.2 15.4% 275.2 14.4% Depreciation of property and equipment 13.4 1.5% 14.9 1.6% 26.6 1.5% 29.4 1.5% Depreciation of lease assets 26.3 2.9% 30.6 3.2% 53.2 3.0% 60.2 3.2% (Reversal) impairment of lease assets (1.0) (0.1%) 2.0 0.2% (2.6) (0.1%) 11.7 0.6% Amortization of intangible assets 13.7 1.5% 13.6 1.4% 27.0 1.5% 27.8 1.5% Net interest expense 10.6 1.2% 12.5 1.3% 19.9 1.0% 27.5 1.4% Income taxes 19.9 2.1 % 20.7 2.2% 37.0 2.1 % 36.5 1.9% Net income from continuing operations 63.2 7.0% 52.6 5.5% 114.1 6.4% 82.1 4.3% Net income from discontinued operations — 0.0% — 0.0% — 0.0% 10.2 0.5% Net income 63.2 7.0% 52.6 5.5% 114.1 6.4% 92.3 4.8% Basic earnings per share (EPS) from continuing operations 0.57 n/m 0.47 n/m 1.02 n/m 0.74 n/m Diluted EPS from continuing operations 0.57 n/m 0.47 n/m 1.02 n/m 0.74 n/m Adjusted EBITDA from continuing operations (note) 146.6 16.1% 142.5 15.0% 275.7 15.4% 282.2 14.8% Adjusted net income from continuing operations (note) 69.6 7.7% 57.7 6.1% 125.7 7.0% 112.0 5.9% Adjusted diluted EPS from continuing operations (note) 0.62 n/m 0.52 n/m 1.12 n/m 1.00 n/m Dividends declared per common share 0.165 n/m 0.155 n/m 0.330 n/m 0.310 n/m note: EBITDA, adjusted EBITDA, adjusted net income, and adjusted diluted EPS are non-IFRS measures (discussed in the Definitions section of the 2020 Annual Report and this MD&A). Comparative EBITDA and adjusted EBITDA figures have been reclassified due to a realignment made to the Definitions included in the 2020 Annual Report. n/m = not meaningful Q2 2021 compared to Q2 2020 We achieved adjusted diluted EPS of $0.62 in Q2 2021, a $0.10 per share or 19.2% increase from $0.52 in Q2 2020, reflecting the continued resilience of our business.