Flint, who has served LAWA and overseen the growth and development of Los Angeles International Airport for the last four years, will replace the retiring Howard Eng in the top job in Toronto.
"Deborah is a proven aviation executive who has been leading Los Angeles World Airports, one of the world's largest passenger and cargo airports, through a period of significant transformation, including the development of an intermodal transit centre," said Doug Allingham, chair of the GTAA's Board of Directors.
"The GTAA Board undertook a global search for a new leader to help guide Toronto Pearson through its next phase of growth, and we are pleased to have found a Canadian-born airport executive with the energy, passion and experience to continue on with our vision to make Toronto Pearson the best airport in the world."
In her role at LAWA, Flint has focused the organisation on the $14-billion modernisation of its terminals, runway improvements, and a comprehensive transit programme that includes roadway improvements and an intermodal transportation facility.
Her deep experience in connecting airports to regional transit networks dates back to her tenure as aviation director of Oakland International Airport where she delivered the BART, a $480 million Airport Rail Project.
"In the world of international airports, Toronto Pearson is a rising and notable star, known for its significant accomplishments on passenger service, growth in passenger traffic, and its leadership in working with both industry and community partners to take a regional perspective on the role a mega-hub airport plays in lifting those around it," said Flint.
"As a Canadian-born airport executive, I consider it a privilege to be able to return home to lead this organisation and ensure it continues to deliver benefits to all of our stakeholders."
Los Angeles World Airports has an impressive story, serving more than 87.5 million passengers and 2 million tonnes of cargo in 2018. In addition to being the 4th busiest passenger airport in the world, it is the only US airport to serve as a hub for four US legacy carriers (Alaska Airlines, American, Delta and United).
It is considered to be one of two North American mega-hub airports, with Toronto Pearson focused on joining the ranks by the end of 2019.
According to GTAA, mega-hub international hub airports serve more than 50 million passengers, with a high percentage of connecting and international passengers.
Flint is a member of the ACI-NA board, appointee to the US DOT Drone Advisory Committee, and chair of the Oversight Committee of the Transportation Research Board's Airport Cooperative Research Program.
Beyond the airport industry, she has served on the Board of the Federal Reserve Bank and is a Director of the Honeywell Corporation.
Current GTAA boss Eng is to retire in March 2020 after six years in Toronto, during which time he has overseen a period of record passenger growth, a dedicated focus on customer service and a dramatic expansion of the airport's retail and service offerings.
"After nearly 40 years running airports around the world, Howard's retirement is a bittersweet moment in the history of Toronto Pearson," stated Allingham.
"We will continue to benefit from his dedication for years to come, as we reap the benefits of the decisions that he made over his eight-year term at Canada's busiest airport."