Siamak Hariri, OAA, AAA, AIBC, SAA, NSAA, NLAA, FRAIC, Intl. Assoc. AIA (Persian: سیامک حریری; born 1958) is a Canadian architect and a founding partner of Hariri Pontarini Architects, a full-service architectural firm based in Toronto, Canada.

Born in Bonn, Germany, Hariri was educated at the University of Waterloo (BES, '79) and Yale University (M.Arch, '85). Upon graduation, he worked at firms in New York and Toronto before founding Hariri Pontarini Architects with David Pontarini in 1994. Hariri holds "deep respect for the transformative potential of architecture and specializes in designing works of enduring value" for private and public clients including the Art Gallery of Ontario, Royal Ontario Museum, Princess Margaret Cancer Centre, and St. Michael's Hospital.

Hariri is a member of the Royal Canadian Academy of Arts, sits on the board of the Design Exchange, and has sat on the advisory board of the Royal Ontario Museum's Contemporary Culture (formerly the Institute for Contemporary Culture) and the Toronto Community Foundation. He served as a member of Waterfront Toronto's Design Review Panel from 2005 until 2010. Hariri has also taught studios at the John H. Daniels Faculty of Architecture, Landscape and Design at the University of Toronto. He has been a lecturer, guest critic, and jury member for organizations across North America and Europe.

He lives in Toronto with his wife, artist Sasha Rogers, and their three children.

In his TED Talk entitled How do you build a sacred space, Hariri shared that the inspiration behind his practice stems from the emotional response that architecture can create: "The school of architecture that I studied at some 30 years ago happened to be across the street from the wonderful art gallery designed by the great architect Louis Kahn. I love the building, and I used to visit it quite often. One day, I saw the security guard run his hand across the concrete wall. And it was the way he did it, the expression on his face—something touched me. I could see that the security guard was moved by the building and that architecture has that capacity to move you. I could see it, and I remember thinking, 'Wow. How does architecture do that?' At school, I was learning to design, but here—here was a reaction of the heart. And it touched me to the core. You know, you aspire for beauty, for sensuousness, for atmosphere, the emotional response. That's the realm of the ineffable and the immeasurable. And that's what you live for: a chance to try."

Over the past three decades, Hariri has established a reputation as a "sculptor working in architecture." His work reflects a commitment to the essentials of architecture, and to every project he brings "a profound interest in light, form, site, material, and craft." His process begins with hand-sketching to establish the initial conceptual design for a project, which is then refined and developed in an iterative process of additional sketching, physical model studies, and digital renderings.

Hariri's portfolio has been honored with over 100 national and international design awards, including several Governor General's Medals in Architecture. With founding partner, David Pontarini, the firm received the 2013 Royal Architectural Institute of Canada's Architectural Firm Award.

In 2014, Hariri was named a Fellow of the Royal Architectural Institute of Canada.