Cindy Tang's sketch of an underwater telescope will welcome visitors to Google.ca on Wednesday.
In her entry, Tang wrote that her illustration symbolizes her wish to explore the largely uncharted deep ocean waters.
Google challenged Canadian kids to design a doodle for the search engine's website with the theme: "If I could invent anything, I would invent…"
Ontario Premier Kathleen Wynne was on hand to congratulate Tang and the 25 regional finalists during a ceremony at Toronto's Royal Ontario Museum.
The winners were selected by judges Chris Hadfield, ROM chief executive Janet Harding, actress Karine Vanasse and Ann Makosinski, a winner in last year's Google Science Fair.
Tang wins a $10,000 scholarship and a computer, while her school will also receive a $10,000 grant.
"I can't believe it yet, it doesn't seem real," said Tang shortly after being named winner.
"I'm happy that I won so that I can give back to my community."
The finalists' artwork will be on display at the ROM until April 27.