| Name | Degree | Discipline | Known for | Notes |
| V. K. Aatre | Graduate | Electrical engineering | Scientist and former head of the Defence Research and Development Organisation | |
| Michael H. Albert | Undergraduate | Mathematics | Rhodes Scholar, professor at University of Otago | |
| Celeste Anderson | Undergraduate | Computer Science | King of the Nerds winner, competitive gamer | |
| Gordon Stewart Anderson | Undergraduate | — | Writer | |
| Mohammad H. Ansari | Graduate | Physics | Fundamental quantum theory research | |
| Andy Anstett | Graduate | Politics | Ministry of Municipal Affairs | |
| Paul Antrobus | Graduate | Psychology | Principal at Baptist Theological Seminary, Kakinada (India) and Psychology Professor at University of Regina, Regina, Saskatchewan (Canada) | |
| Omer Arbel | Undergraduate | Environmental studies | Designer, sculptor, creative director of Bocci | |
| Karen Autio | Undergraduate | Mathematics and computer science | Writer of children's fiction | |
| Calvin Ayre | Undergraduate | Science and Business | Bodog founder | |
| Ricardo Baeza-Yates | Graduate | Computer science | Director of Yahoo! Research labs | |
| Bill Ballinger | Undergraduate | Political science | Member of the Legislative Assembly of Ontario | |
| Lisa Feldman Barrett | Graduate | Psychology | Northeastern University professor | |
| Romesh Batra | Graduate | Mechanical engineering | Virginia Polytechnic Institute and State University professor | |
| Keith Beavers | Undergraduate | Kinesiology | Competed in swimming at the 2004 Summer Olympics | |
| Gordon Bell | Undergraduate | Computer science | QNX co-creator | |
| David Berman | Undergraduate | Computer science | Fellow of the Society of Graphic Designers of Canada | |
| Peter Besler | Undergraduate | Chemistry | Investment banker | |
| Art Binkowski | Undergraduate | Psychology | Heavyweight boxer | |
| Don Boudria | Undergraduate | Politics | Canadian Member of Parliament and Cabinet Minister | |
| Marie Bountrogianni | Undergraduate | Arts | Member of Ontario Parliament, Minister of Intergovernmental Affairs, and dean of the G. Raymond Chang School of Continuing Education at Ryerson University | |
| Mark Bourrie | Undergraduate | History | Lawyer, author, and winner of the RBC Taylor Prize for literary non-fiction | |
| Gail Bowen | Graduate | English | Playwright and writer of mystery novels | |
| Brad Bradford | Graduate | Planning | Toronto City Councillor | |
| Mike Bradley | Undergraduate | Athletics | Canadian Football League running back | |
| Peter Braid | Undergraduate | International relations | Member of Parliament | |
| Andrew Brandt | Undergraduate | Business | Former Canadian cabinet minister | |
| Fiona Brinkman | Undergraduate | Biochemistry | Associate professor at Simon Fraser University | |
| Alison Brooks | Undergraduate | Architecture | Stirling Prize Award-winning Architect | |
| Edward Burger | Graduate | Mathematics | Professor at Williams College | |
| Amanda Burk | Undergraduate | Fine Arts | Artist, associate professor at Nipissing University | |
| Vitalik Buterin | Dropout | Computer science | Co-founder of Ethereum, co-founder of Bitcoin Magazine | |
| Wayne Cao | Undergraduate | Computer science | Member of the Legislative Assembly of Alberta | |
| Colin Carrie | Undergraduate | Politics | Member of Parliament | |
| Jeromy Carriere | Undergraduate | Computer science | Computer architect | |
| Bardish Chagger | Undergraduate | Science | Member of Parliament | |
| David Cheriton | Graduate | Mathematics | Stanford University professor and Granite Systems co-founder | |
| Václav Chvátal | Graduate | Mathematics | Canada Research Chair in Combinatorial Optimization and former professor at McGill and Stanford | |
| Ian Clark | Graduate | Earth science | Professor in the Department of Earth Sciences at the University of Ottawa | |
| George Elliott Clarke | Undergraduate | Entertainment | Poet and playwright; Governor General's Award for poetry recipient | |
| Rod Coutts | Undergraduate | Electrical Engineering | Founder of Teklogix; namesake of the Rod Coutts Engineering Lecture Building at University of Waterloo | |
| Clifford Cunningham | Undergraduate | Physics & Classical studies | Astronomer | |
| Julie E. Czerneda | Undergraduate | Literature | Science fiction and fantasy author | |
| Heather Dale | Undergraduate | Entertainment | Celtic singer | |
| Liane Davey | Graduate | Industrial/Organizational Psychology | Leadership consultant, public speaker, and New York Times bestselling author | |
| Erik Demaine | Graduate | Computer science | Youngest professor ever at MIT | |
| Dan Dodge | Undergraduate | Computer science | QNX co-creator | |
| Andrew Drummond | Undergraduate | Arts | Frances Hodgkins Fellow | |
| Richard Ducharme | Undergraduate | Civil engineering | General Manager of Transportation for Edmonton | |
| Tom Duff | Undergraduate | Computer science | Computer scientist | |
| Garfield Dunlop | Undergraduate | Politics | Member of the Legislative Assembly of Ontario | |
| David Eby | Undergraduate | English | Premier of British Columbia | |
| Fred Eisenberger | Undergraduate | — | Politician | |
| Jon Evans | Undergraduate | Engineering | Arthur Ellis Awards winner | |
| Anne Fleming | Undergraduate | English | Fiction writer | |
| Joe Fontana | Undergraduate | Chemistry | Member of Parliament | |
| Godwin Friday | Graduate | History | Prime Minister of Saint Vincent and the Grenadines | |
| John Friedlander | Graduate | Mathematics | Fellow of the Royal Society of Canada and American Mathematical Society and winner of the CRM-Fields-PIMS prize | |
| Curwin Friesen | Undergraduate | Economics | Chief executive officer of Friesens | |
| James Alan Gardner | Graduate | Mathematics | Science fiction author | |
| J. Alan George | Graduate | Computer science | Dean of the University of Waterloo Faculty of Mathematics | |
| Garth A. Gibson | Undergraduate | Computer Science | Computer scientist at Carnegie Mellon University | |
| Brad Goddard | Undergraduate | Theatre | Actor | |
| W. G. Godfrey | Graduate | Canadian history | Canadian historian | |
| Gaston Gonnet | Graduate | Computer science | Computer scientist and entrepreneur | |
| Gary Goodyear | Undergraduate | Politics | Canadian Member of Parliament | |
| Rick Green | Undergraduate | Entertainment | Comedian and member of The Frantics | |
| Chris Hadfield | Graduate | Mechanical engineering | Astronaut, Commander of the International Space Station (2013) | |
| Fariborz Haghighat | Graduate | System Design Engineering | Professor at the Concordia University | |
| Ann Hansen | Undergraduate | — | Urban guerrilla | |
| Dianne Haskett | Undergraduate | Arts | Mayor of London, Ontario | |
| Deen Hergott | Undergraduate | — | Chess International Master | |
| Cyd Ho | Undergraduate | Politics | Member of the Legislative Council of Hong Kong | |
| Glenn Howard | Undergraduate | Environmental studies | Three-time World Curling Champion | |
| Kimmo Innanen | Graduate | Mathematics | Astronomer and professor | |
| David Johnson | Graduate | Mathematics | Mayor of East York, Ontario | |
| Rupi Kaur | Undergraduate | English | Poet, illustrator, and author; best known for her debut book, Milk and Honey | |
| Humayun Akhtar Khan | Undergraduate | Business mathematics | Commerce Minister of Pakistan | |
| Arounna Khounnoraj | Graduate | Fine arts | Multi-disciplinary artist, teacher, author and co-founder of Bookhou | |
| Don Knight | Undergraduate | Accounting | Former member of the Legislative Assembly of Ontario | |
| Tony Knowles | Graduate | Physical chemistry | President of the British Columbia Institute of Technology | |
| Michelle Lam | Graduate/undergraduate | Accounting | Founder and CEO of True & Co., a direct-to-consumer digital intimate apparel brand, headquartered in San Francisco, California | |
| Steven Lee | Undergraduate | Science | Founder of Visibly/Opternative, CEO of VisionPros | |
| Mike Lazaridis | Undergraduate | Electrical engineering | Research in Motion founder | |
| William Lawrence Kocay | Graduate | Mathematics | Professor of mathematics | |
| Serge LeClerc | Undergraduate | Sociology | Co-author of Untwisted | |
| William C. Leggett | Graduate | Zoology | Principal of Queen's University | |
| Martha Lenio | Undergraduate | Mechanical Engineering | Commander of the NASA human performance study Hawaiʻi Space Exploration Analog and Simulation (HI-SEAS) | |
| Rasmus Lerdorf | Undergraduate | Systems Design Engineering | PHP creator | |
| David X Li | Graduate | Actuarial science | Pioneer of Gaussian copula pricing models for collateralized debt obligations | |
| Michael Lysko | | — | Former Canadian Football League commissioner | |
| Rob MacIsaac | Undergraduate | Economics | Former Mayor of Burlington, Ontario; President of Hamilton Health Sciences | |
| Manas K. Mandal | Graduate | Biology | Director of the Defence Institute of Psychological Research | |
| Scott Manning | Undergraduate | — | Stunt pilot and CFL veteran | |
| Peter Masak | Undergraduate | Mechanical engineering | Glider pilot | |
| Ingrid Mattson | Undergraduate | — | Islamic Society of North America president | |
| Konris Maynard | Undergraduate | — | Winner of the Saint Kitts and Nevis National Calypso Show | |
| E. J. McGuire | Graduate | Psychology | Former director of the NHL Central Scouting Services | |
| David I. McKay | Undergraduate | Mathematics | Current President & CEO of Royal Bank of Canada | |
| Peter McLaren | Undergraduate | English literature | Critical pedagogy | |
| Nenad Medić | Undergraduate | — | Professional poker player | |
| Stella Meghie | Undergraduate | — | Film director and screenwriter | |
| James G. Mitchell | Undergraduate | Computer science | Computer scientist | |
| Parker Mitchell | Undergraduate | — | Engineers Without Borders co-founder | |
| Faron Moller | Graduate | Computer science | Computer scientist | |
| David Morrell | Undergraduate | Arts | Novelist for First Blood and the creator of the character John Rambo.; the book was adapted into the 1982 film of the same name | |
| Michele Mosca | Undergraduate | Computer science | Co-founder of the IQC and the PITP | |
| Heather Moyse | Undergraduate | Kinesiology | Two-time Olympic gold medalist in bobsleigh; represented Canada's national rugby team at both the 2006 and 2010 Women's Rugby World Cup | |
| Walt Neubrand | Undergraduate | — | Keeper of the Stanley Cup | |
| Kevin O'Leary | Undergraduate | Environmental studies | Canadian businessman, author, politician, and television personality | |
| Paul van Oorschot | Graduate | Cryptography | Carleton University professor | |
| Chamath Palihapitiya | Undergraduate | Electrical engineering | Venture capitalist, engineer, SPAC sponsor and the founder and CEO of Social Capital | |
| Steve Paul-Ambrose | Undergraduate | Science and Business | Poker player | |
| Cole Pearn | Graduate | Mechanical engineering | NASCAR crew chief | |
| Jean Poirier | Undergraduate | Environmental studies | Member of the Legislative Assembly of Ontario | |
| Yuri Quintana | Graduate | Engineering | Chief Division of Clinical Informatics, Beth Israel Deaconess Medical Center and Harvard Medical School | |
| Karen Redman | Undergraduate | Politics | Canadian Member of Parliament | |
| William Reeves | Undergraduate | Entertainment | Academy Award recipient for Toy Story | |
| John Reimer | Undergraduate | Education | Member of Parliament | |
| Neil Robertson | Graduate | Mathematics | Professor at the Ohio State University | |
| Robert Rosehart | Graduate | Engineering | President of Wilfrid Laurier University | |
| George Roter | Undergraduate | Engineering | Co-CEO of Engineers Without Borders (Canada) | |
| Bimal Kumar Roy | Graduate | Mathematics | Cryptologist | |
| Sandra Sabatini | Graduate | English literature | Writer | |
| Khaled Al Sabawi | Undergraduate | Computer science | Canadian entrepreneur; named one of the "World's Top Energy Entrepreneurs" by Global Post in 2010 | |
| Reihaneh Safavi-Naini | Graduate | Cryptography | University of Wollongong professor | |
| George Samis | Graduate | Political science | Member of the Legislative Assembly of Ontario | |
| Liz Sandals | Graduate | Mathematics | Member of Ontario Parliament | |
| Prem Saran Satsangi | Graduate | Electrical engineering | Spiritual leader of Radhasoami faith, Dayalbagh, chairman (ACE), Dayalbagh Educational Institute, ex-vice-chancellor of Dayalbagh Educational Institute, dean (academics) at IIT Delhi, system scientist, physicist | |
| Jonathan Schaeffer | Graduate | Researcher | Professor at the University of Alberta | |
| Beckie Scott | Undergraduate | English | Olympic gold medalist, the first Canadian and first North American woman to win an Olympic medal in cross-country skiing; Officer of the Order of Canada and Chair of the World Anti-Doping Agency | |
| Jonathan Seet | Undergraduate | | Singer-songwriter; released albums Melatonin and Arousal Disasters | |
| Hersh Shefrin | Graduate | Mathematics | Behavioral finance | |
| Ron Sider | Undergraduate | Theology | Founder of Evangelicals for Social Action | |
| Bruce Smith | Undergraduate | Arts | Member of the Legislative Assembly of Ontario | |
| James K. A. Smith | Undergraduate | Philosophy | Associate professor of philosophy at Calvin College | |
| Steve Smith | Undergraduate | Entertainment | Actor in The Red Green Show | |
| Moustafa Aly Soliman | Graduate | Chemical Engineering | Pioneered the use of sulfur compounds in thermochemical cycles for hydrogen production and the use of nano-palladium to catalyze partial oxidation of ethane to acetic acid | |
| Kevin Strain | Graduate/undergraduate | Accounting | President & CEO of Sun Life Financial | |
| Thomas Strothotte | Graduate | Computer science | Rector of the University of Rostock | |
| John Sullivan | Undergraduate | — | Canadian Football League player | |
| Vahid Tarokh | Graduate | Engineering | Professor at Harvard University | |
| Andrew Telegdi | Undergraduate | Politics | Canadian Member of Parliament | |
| Brad Templeton | Undergraduate | Software | Software engineer and entrepreneur | |
| Disguised Toast | Undergraduate | Computer Science/Mathematics | Gamer, influencer | |
| Carsten Thomassen | Graduate | Mathematics | Professor of graph theory at the Technical University of Denmark | |
| Susan Tighe | Graduate | Civil engineering | Canada Research Chair in Sustainable Pavement and Infrastructure Management | |
| Claire J. Tomlin | Undergraduate | Science | Researcher | |
| Eric Veach | Undergraduate | Computer Science | Computer Graphics | |
| Douglas N. Walton | Undergraduate | Arts | Author on argumentation, logical fallacies, and informal logic | |
| Judy Wasylycia-Leis | Undergraduate | Political science | Manitoba cabinet minister | |
| Elizabeth Weir | Undergraduate | Political science | Leader of the New Brunswick New Democratic Party | |
| David A. Weitz | Undergraduate | Physics | Mallinckrodt Professor of Physics & Applied Physics and professor of Systems Biology at Harvard University and director of the Harvard Materials Research Science & Engineering Center | |
| Chris Williams | Undergraduate | Fine arts | Animator, film director, screenwriter, and voice actor | |
| Jeff Wincott | Undergraduate | Kinesiology | Actor and athlete | |
| Elizabeth Witmer | Graduate | Politics | Member of Ontario provincial parliament | |
| Alexander Wong | Graduate/undergraduate | Computer Science | Scientist | |
| Bob Wong | Undergraduate | Science | Member of the Legislative Assembly of Ontario | |
| Ardeth Wood | Graduate | Philosophy | Died in a forcible drowning; the two-year search for her killer was one of the largest manhunts in Canada | |
| Steven Woods | Graduate/undergraduate | Mathematics | Founder of Quack.com | |
| John Wynne | Undergraduate | Sports | Ice hockey defenceman | |
| Tim Wynne-Jones | Undergraduate | Literature | Author of children's literature | |
| Fangjin Yang | Undergraduate | Electrical engineering | Co-founder and CEO of Imply; co-creator of Druid | |
| Catalina Yue | Undergraduate | Arts | Miss Universe Canada | |
| Matei Zaharia | Undergraduate | Computer science | Co-founder and CTO of Databricks, creator of Apache Spark, and co-creator of Apache Mesos | |