Fernley will report directly to Zak Brown, CEO of McLaren Racing, and will lead the McLaren 2019 Indianapolis 500 programme, when Fernando Alonso will attempt to secure the Triple Crown of motorsport.
Fernley is a widely experienced and respected figure within the world of motorsport, with relationships across the industry. His career portfolio most recently includes a role as Deputy Team Principal at Force India, and previously a focus on North American motorsport, including successful periods in IndyCar.
His appointment is consistent with McLaren Racing's plan to run its IndyCar programme as a separate entity to its Formula 1 activities.
Fernley will build and lead a technical team entirely focused on the 2019 Indy 500, while helping to evaluate the feasibility of a longer-term McLaren involvement in IndyCar.
Further details on the 2019 McLaren Indy 500 project will be shared in due course.
"Bob is a fantastic operator and someone I respect greatly," said Zak Brown. "His experience and leadership will be essential for us on this project. He is particularly talented at putting effective teams together and extracting maximum performance with finite resources. The Indy 500 is no easy race and Bob's is a key role, so I'm delighted he's on board."
"Heading back to The Brickyard will be a very special experience for me and I am proud to be leading this McLaren project and team," added Fernley. "The 500 is a hell of a challenge and we have incredibly strong competitors to overcome if we're to be successful. We will need to prepare well for the month of May and that work starts now."