Parkes, who joins from business travel specialist Clarity, takes over later in the year, when Wait leaves to become chief operating officer at Southall Travel Group.
Parkes was previously chief commercial officer for Portman Travel prior to its merger with Clarity and served as product and marketing director after the merger. Parkes has also worked for Etihad and former airline Bmi.
In his new role, Parkes will aim to boost membership from the current 40 TMCs and raise awareness of issues that impact the business travel sector, ensuring it has a high profile among policy makers.
GTMC chairman Paul Allan said: “I have been lucky enough to cross career paths with Adrian Parkes in the past and I am thrilled to have the opportunity to work him again.
“He brings invaluable experience as both a TMC Member and an industry partner of the GTMC. Adrian will lead the GTMC in its next chapter following Paul Wait’s tenure at the helm.
“Paul’s entrepreneurial approach to leadership and driving change in the business travel sector has been visionary and he leaves the GTMC in the best possible position to tackle the next raft of sector challenges.
“The Board and I are looking forward to the future success and growth of the GTMC under Adrian’s expert guidance.”