The survey results, announced by Turkish Youth and Sports Minister Suat Kilic, found that 83 per cent of Istanbul residents and 76 per cent of the national population back the Olympic effort.
"Eighty-three per cent of Istanbul's population supports the bid," Kilic said. "That's 11 million people who want a city which bridges East and West to host the games."
The new bid slogan highlights the city's unique geographic location straddling Europe and Asia. It was inspired by Istanbul's Bosporus Bridge, which connects the city's European and Asian sides.
"Istanbul is a bridge between East and West, between Europe and Asia, and between civilizations, cultures and faiths," Kilic said. "I hope that this slogan brings success not only to Turkey but to everyone who shares the Olympic values."
The slogan and survey results were made public on the second day of the IOC evaluation commission's four-day assessment of Istanbul's bid. The team has already visited rival bidders Tokyo and Madrid.
The bid committee has been touting Istanbul's ability to stage the games on two continents to set it apart from Tokyo and Madrid. It is also pitching Turkey's growing economy and is promising new and modern venues. Istanbul would bring the games to a new region and to a mainly-Muslim country for the first time.
"Istanbul 2020 is delighted that Istanbul's fifth bid to host one games on two continents, for the first time ever in Turkey, has not only captured the world's attention, but has drawn upon the passion of our sports-loving nation," bid chairman Hasan Arat said.
Istanbul is bidding for the Olympics again after unsuccessful attempts for the games of 2000, 2004, 2008 and 2012.
Earlier, a leading Turkish businessman assured the IOC of the private sector's support Istanbul's bid.
Ali Koc, board member of Turkey's Koc Holding, said the country's business community is ready "to help one of the most important projects in Turkey's history."
In January, the Istanbul bid secured $20 million in sponsorship from seven leading Turkish companies, including Koc Holding.
The IOC will select the 2020 host city by secret ballot at its general assembly in Buenos Aires on Sept. 7.