The move marks Miller's first role in football.
The Englishman has a background in aviation and arrives from Ferrovial Vertiports. He was also with the Manchester Airport Group.
Darren Eales, Newcastle's CEO, said: "Brad is an exceptional operator and we are delighted to welcome him to the Newcastle United family. He brings with him an outstanding track record in both operational and developmental projects, and his creative, collaborative and strategic leadership will be a huge asset to us as we continue to strive for best-in-class in all that we do."
Miller said: "I am looking forward to helping Newcastle United to move forward with its ambitious, sustainable development plans and to working alongside such dedicated and passionate people. It is an incredibly exciting and unique time for everyone involved with the club."