The appointment comes after private equity investor Endless LLP took up a majority stake in the Manchester-headquartered company in July.
In his long career McEwan has served as Abta chairman, retail director for Tui and chief executive for Advantage Travel Centres.
He is currently chairman of Holidaysplease, EFR Travel, Latin Routes, Ski Solutions and Pebble Travel.
Chief executive Clive Wratten said: “John brings a huge wealth of experience and I’m confident that together we can deliver on the massive potential within CTI.”
McEwan added: “This is an exciting time to be joining CTI. I know Clive and the team have very ambitious plans to grow the business in this dynamic and fast moving sector and I look forward to working with them to achieve this.”
Wratten, Mathew Deering and Vicky Godliman are also on the board.
CTI employs around 125 people across offices in Manchester, Bristol, Leeds, Liverpool and Hull.
