The chief of Scottish Rugby will take up the role at Celtic Park this summer when Peter Lawwell steps down from the role he has held since 2003.
In his first interview after the announcement, McKay stated his eagerness to achieve success at a club he’s supported all his life.
He said: "It is with great pride and enthusiasm that I look forward to beginning my new role as chief executive officer of Celtic. Celtic is the premier football club in Scotland and one of the most recognisable football brands globally, with our fans and sporting ethos known and respected throughout the world.
"I look forward to working with Peter and the board to ensure a seamless transition. In Peter Lawwell I can think of no better example to follow. His experience and leadership have been the cornerstones of Celtic's success, success that I will now look to build on going forward. I thank him and the wider board for their support and encouragement.
"Of course I understand that Celtic is more than just about financial results off the pitch and football results on the pitch. Celtic is built on a charitable ethos that underpins everything that happens at the football club. Developing and nurturing the rich Celtic ethos with all our supporters and stakeholders is a key component of my role going forward. I’m looking forward to supporting and building upon the great work carried out by Celtic FC Foundation to ensure that this remains at the heart of the Celtic way.
"Having spoken with Dermot Desmond I know I will have a shareholder who cares deeply about the club and who will take the time to provide advice and the benefit of his experience to help me in my new role. I thank him for his confidence and support as we embark on our journey.
"I relish the opportunity to start working with my new team, the footballing and playing staff and most importantly the supporters and to see what we can achieve together for this great club, delivering the success that Celtic is built upon."