Investor Presentation August 4, 2021

Cautionary Note Regarding Forward-Looking Statements

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Certain statements contained in this presentation constitute forward-looking information and statements within the meaning of applicable securities law (collectively, "forward-looking statements"). Forward-looking statements in this presentation include, but are not limited to: our financial targets (including our annual net revenue growth, adjusted EBITDA, and net income targets; employee count; and ROIC target), our anticipated business and geographical mix, our expectations regarding economic and industry trends in the sectors and regions in which we operate, our acquisition strategy, our capital deployment strategy, and our overall growth strategy. These statements provide information about management’s current expectations and plans relating to the future. Readers are cautioned that this information may not be appropriate for other purposes. Stantec does not undertake any obligations to publicly update or revise any forward-looking statements except as required by law.

By their nature, forward-looking statements require us to make assumptions and are subject to inherent risks and uncertainties. Readers are cautioned not to place undue reliance on our forward-looking statements since a number of factors could cause actual future results, conditions, actions, or events to differ materially from the targets, expectations, estimates, or intentions expressed in these forward-looking statements. Risk factors include, but are not limited to, the impacts of the COVID-19 pandemic, the risk of an economic downturn, decreased spending in the private and/or public sectors, changing market conditions for Stantec’s services, and the risk that Stantec fails to capitalize on its strategic initiatives. Investors and the public should carefully consider these factors, other uncertainties, and potential events, as well as the inherent uncertainty of forward-looking statements when relying on these statements to makedecisions about our company. For more information about how other material risk factors could affect our results, please refer to the Risk Factor section in our 2020 Annual Report and Q2 2021 Management’s Discussion and Analysis incorporated herein by reference.Readers can access these documents by visiting EDGAR on the SEC website at sec.gov or by visiting the CSA website at sedar.com or on Stantec’s website at stantec.com.

In determining our forward-looking statements, we consider material factors including assumptions about the performance of the Canadian, US, and global economies in 2021 and beyond and their effect on our business. Unless otherwise indicated, all amounts expressed in Canadian dollars.

Stantec at a glance

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65+ YEARSOf Uninterrupted Profitability

CDN $6.7B(2)

Market Capitalization

STNTSX & NYSE

350Offices Worldwide

22,000Employees Globally

7.6%10-Year Adjusted Diluted

EPS CAGR(1)

1. Q2 20212. August 4, 2021

Q2

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Q2 2021

Executing our strategy Net RevenueAdjusted EBITDA Margin

$908M 16.1%2.2% increase on a constant currency basis

1.1% increase

AdjustedDiluted EPS Backlog

$0.62 $4.6B19.2% increase 6.0% organic growth

since Dec 31, 2020. Additional $1.2B of notified awards not yet in backlog.

Notes: (1) CDP Website - October 14, 2020 (2) ISS Sustainability Suite – September 1, 2021 (3) Sustainalytics website - January 7, 2021

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CDP (1)

ScoreISS ESG (2)

Quality ScoreSustainalytics (3)

ESG Risk Rating

2020 2019 2018 E S G

A- A- A- 1 1 1 Low

Net Zero #5 #1Carbon neutral

for 2022, then

net zero for 2030

Ranked fifth

most sustainable

corporation

in the world

Ranked most

sustainable

corporation

in North America

Our Operational Pledge 2021 Corporate Knights Global 100

We are a proven sustainability leader

Diversified Global Footprint – Local Presence

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51%

30%

19%

Distribution of Net Revenue

United States Canada Global

$3.6BTTM Q2 2021

$736M

BUILDINGSWATER

$771M

Engineering, Architecture and Environmental Services

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BUSINESS OPERATING UNITS (TTM Q2 2021 Net Revenue)

ENVIRONMENTAL SERVICES

$989M $569M

INFRASTRUCTUREENERGY & RESOURCES

$501M

Signatory to the UN Global Compact Stantec is a signatory to the UN Global Compact and partners with clients to promote the achievement of the UN’s Sustainable Development Goals

Roadways

Community Dev

Transit & Rail

Bridges

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InfrastructureFront-end design and engineering services, construction management, and inspection work for private and public sector clients

150+ 12 28%Envision

SustainabilityProfessionals

Envision-certifiedprojects

of Q2 YTD 2021 net revenue

United States

Canada

Global

Net revenue by geography Q2 YTD 2021

Net revenue by Sector Q2 YTD 2021

United States

Canada

Global

Conveyance

Wastewater Treatment

Water Treatment

Water Resources

Stormwater

Enterprise Systems

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WaterEngineering, design, construction management, financial and enterprise management, program and asset management, and intelligent platforms for public and private sector clients

1,650 67 22%water treatment

facilitiesbillion liters of water

treated every dayof Q2 YTD 2021

net revenue

Net revenue by geography Q2 YTD 2021

Net revenue by sector Q2 YTD 2021

United States

Canada

Global

HealthcareCommercialCivicEducationIndustrialAirportsWorkplace

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BuildingsPre-design, design, and construction administration services in planning, architecture, interior design, buildings engineering, and sustainability and building performance for vertical infrastructure

650+ 35+ 21%LEED-certified

projectsnet zero-designed

buildingsof Q2 YTD 2021

net revenue

Net revenue by geography Q2 YTD 2021

Net revenue by sector Q2 YTD 2021

United States

Canada

Global

WaterOil & GasBuildingsPower & DamsTransportationCommunity DevMining

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Environmental ServicesPlanning and permitting services for private sector clients, and remediation activities for private and public sector clients

40,000+ 1,000 16%acres

restoredmiles of streams and

rivers restoredof Q2 YTD 2021

net revenue

Net revenue by geography Q2 YTD 2021

Net revenue by sector Q2 YTD 2021

United States

Canada

Global

Mining

Power

Oil & Gas

Waterpower

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Energy & ResourcesIndustrial engineering services for private sector energy, resource, and power clients

37+ GW 115+ GW 13%solar & wind renewable

energy generation capacitydelivered

hydro renewableenergy generationcapacity delivered

of Q2 YTD 2021 net revenue

Net revenue by geography Q2 YTD 2021

Net revenue by sector Q2 YTD 2021

Our commitment to a robust ESG strategy

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UN Sustainable Development Goals (SDGs)

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GROWING CONTRIBUTION TO UN SDGs AS MEASURED BY GROSS REVENUE

$- $1,000 $2,000 $3,000 $4,000 $5,000

2019

2020

Gross Revenue ($ millions)

Other

49%

45%

Strategic growth priorities aligned with UN SDGs

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SMART CITIES AND URBAN PLACES

ENERGY TRANSITION

COASTAL RESILIENCE

ECOSYSTEMRESTORATION

Sustainable Cities Life on Land

Reduced Inequalities

Affordable and Clean EnergyA

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Climate Action

Life Below Water

Sustainable Cities and Communities

US$300B1 US$9,000B1 US$1,700B2 US$13,040B3

1) United Nations by 2030 2) Navigant Research by 2030 3) IEA by 2025

Climate Action

Life Below Water

Climate Action

Our sustainability pledgesCA

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Carbon Neutral Net Zero

2022 2030Pledged to be carbon neutral

for our 2022 operational

emissions.

Committed to set 1.5ºC

science-based emissions

reduction targets.

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Social leadership

Community Engagement (CE) Inclusion & Diversity Gender Pay Equity

$45M by 2025Committed to investing a further $15 million through our CE program, taking our total to $45 million since starting our CE program in 2007

5,100+ Global community partnerships in the history of our CE program

$646KGrants for STEM in 2020

$481K Scholarships funded in 2020

$200K Annual Equity & Diversity Scholarship launched in 2020

We support I&D through partnerships to gain access to top talent from BIPOC communities, sponsoring scholarships and internships for underrepresented and underprivileged students, and through reviewing our internal practices to identify and remove bias.

Named on the 2020 Bloomberg Gender Equality Index

Participant in Global Compact Network Canada—Gender Equality Leadership in the Canadian Private Sector

Signatory to the UN Women Empowerment Principles

C-suite is 38% female and 25% are people of color

A review of our pay practices found that women have received higher average pay increases since 2018, and are being promoted at a higher rate, than men during the same period.

3%Base pay gap on a median comparatio basis in North America

Voluntary Turnover

<8%Average voluntary turnover rate; excellent employee retention with turnover ~3% lower than our industry average

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A diverse board of directors with exceptional backgrounds

38% Female

Certified Integrated Management System:

• Quality Management (ISO 9001)

• Occupational Health & Safety Management (OHSAS 45001:2018)

• Environmental Management (ISO 14001:2015)

• IT Service Management System (ISO 20000-1:2018)

• Information Security System ISO 27001 (in progress)

• Business Continuity Planning• Pandemic Preparedness• Internal Practice Audits

Robust IT security processes and practices:

• Next-generation security systems• Cybersecurity awareness training for employees• Compliance with privacy laws including the

General Data Protection Regulation (European Union), Defense Federal Acquisition Regulation Supplement (United States), and Cyber Essentials Plus (United Kingdom)

Good Governance

Q2 2021

Financial Performance

Theresa Jang - Executive Vice President and Chief Financial Officer

Q2

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Q2

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Q2 2021 results

(1) EBITDA, adjusted EBITDA, adjusted net income, and adjusted diluted EPS are non-IFRS measures discussed in the Definitions section of this quarter's MD&A.

Adjusted Net Income and EPS($ millions, $ per share)

Adjusted EBITDA and margin($ millions, %)

Q2 2021 Q2 2020 Change

(In millions of Canadian dollars, except per share amounts and percentages) $ $

% Year-over-year

change

Net revenue 908.3 951.1 (4.5)

Gross margin 483.3 489.7 (1.3)

Administrative and marketing expenses 341.3 344.0 (0.8)

EBITDA from continuing operations(1) 146.1 146.9 (0.5)

Net income from continuing operations 63.2 52.6 20.2

Diluted earnings per share (EPS) from continuing operations 0.57 0.47 21.3

Adjusted EBITDA from continuing operations(1) 146.6 142.5 2.9

Adjusted net income from continuing operations(1) 69.6 57.7 20.6

Adjusted diluted EPS from continuing operations(1) 0.62 0.52 19.2

Impact of stronger Canadian Dollar on US earnings

Q2 21 vs Q2 20 YTD 21 vs YTD 20

US$1 to CAD $1.22 vs $1.39 $1.25 vs $1.37

Reduction in

Revenue $60.9M $90.5M

Adjusted EBITDA $8.2M $11.6M

Adjusted net income $4.0M $5.5M

Adjusted diluted EPS $0.04 $0.05

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Balance sheet strength

(1) Net debt to adjusted EBITDA and days sales outstanding are non-IFRS measures discussed in the Definitions section of this quarter's MD&A.

Net debt to adjusted EBITDA(1) Days sales outstanding

0.9x at June 30, 2021

Target range1.0 - 2.0x

76 days at June 30, 2021

Target decreased to <80 days

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Quarterly and TTM Free cash flow(1)

($ millions)

Capital returned to shareholders($ millions)

(1) Free cash (out)flow is defined as operating cash flows less capital expenditures and net payment of lease obligations.

Liquidity and capital allocation(Comparisons to YTD 2020)

• $74 million decrease in free cash flow (1) YTD

• $51 million used to repurchase shares YTD

• ~$800 million in credit capacity largely undrawn

Cash flow from continuing operations (millions of Canadian dollars) YTD 2021 YTD 2020

Inflow (Outflow)

Operating 133.9 207.6

Investing (53.9) (31.8)

Financing (149.3) (124.6)

Net (69.3) 51.2

2021 Outlook – Earnings guidance increasedAdjusted diluted EPS growth target now 4% -7% (1)

(1) In setting targets and guidance, the average value for the US dollar is assumed to be $1.22 and for the GBP $1.72 for the remainder of the year. Adjusted EBITDA, adjusted net income, adjusted diluted EPS, and adjusted return on investment capital (ROIC) are non-IFRS measures discussed in the Definitions section of the 2020 Annual Report and this quarter’s MD&A. Adjusted ROIC is calculated annually at the end of the year.

2021 Targets – Updated2021 YTD Performance

5.0% 6.0% 7.0% 8.0%Adjusted net income(1)

(% of net revenue)

7.0%

Geography 2021 Regional Outlook

United States • Slower start to recovery

Canada • Slightly stronger than expected

Global • Slightly stronger than expected

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Guidance for 2021 full-year organic net revenue growth remains unchanged; expected to be 1 to 5% on a constant currency basis

8.0% 9.0% 10.0% 11.0%Adjusted Return on invested capital (1)

Calculated at year-end

Adjusted EBITDA(1)

(% of net revenue)14.0% 15.0% 16.0% 17.0%

15.4%

Upward revision of guidance ranges

Stantec ideally positioned to benefit from US stimulusBipartisan Senate bill would boost spending ~6% above ACEC forecast over next six years(1)

Addressable areas of bipartisan bill (2) Funding

Transportation InfrastructureRoads, bridges major projects; Passenger and freight rail; Public transit; Airports; Transportation safety; Electric vehicles and EV infrastructure

$267B

WaterPorts and waterways; Clean drinking water; Resilience; Western water infrastructure and Upgrades

$122B

Power InfrastructureUpgrade aging power infrastructure; Building new, resilient transmission lines to facilitate renewable energy expansion

$65B

Environmental RemediationEnvironmental Remediation of idle industrial and energy sites

$21B

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(1) The American Council of Engineering Companies (ACEC) 2021-26 Engineering Industry Outlook (June 28, 2021)(2) Bipartisan Infrastructure Investment and Jobs Act – Updated Fact Sheet (August 2, 2021)

$300

$320

$340

$360

$380

$400

$420

$440

2018 2019 2020 2021 2022 2023 2024 2025 2026

ACEC Engineering and Design Services Forecast (1)

($ billions in output in A/E Services)

Baseline ACEC Forecast Bipartisan ACEC Forecast

Committed to our strategic targets for 2023

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Maximizing long-term, sustainable value through our value creators

Net Revenue

Adjusted Earnings per Share

>10% >11%CAGR CAGR

Adjusted EBITDA Margin

Adjusted Return on Invested Capital

16-17% >10%Of Net Revenue