McNamara will join the airline later this year, following the completion of a near 20-year stint at the association. He has been director-general for the past four years.
His responsibilites will include leading Flybe’s PR and public affairs activities, as well as promoting the airline’s "purpose, vision and strategy" internally and to investors, media and politicians, Flybe said in a statement.
The role has been vacant since 2015, following Andrew McConnell's departure after a year in the post. A spokeswoman at Beattie - Flybe's PR agency - said the airline was now looking to invest more in comms.
McNamara said: "I have a passion for regional aviation and am very excited to be able to work with the team to further develop, position and communicate Flybe as Europe’s leading regional airline."
He will report to Flybe CEO Christine Ourmieres-Widener, who was appointed in January following almost two years as chief global sales officer at American Express Global Business Travel, her LinkedIn profile states.
During McNamara's tenure at the association, he has helped promote the contribution that regional airlines make to Europe’s economic prosperity, the Flybe statement said.
According to data provided by the UK Civil Aviation Authority, Flybe offered over 95,000 domestic flights in 2016 – the most of any carrier in the UK.