Lilleyman, a mining engineer, left Rio in May this year after 25 years with the miner in roles including president of Pilbara operations.
He will join FMG on January 1.
“We are delighted to welcome Greg to Fortescue for the next phase of our journey to be the safest, lowest cost, most profitable iron ore producer,” FMG CEO Nev Power said.
“Greg brings a wealth of industry knowledge with a personal style and approach strongly aligned with Fortescue’s values and culture.
“His extensive experience in leading safety and operational excellence combined with his thorough knowledge and passion for technology and innovation, provides for the further development of Fortescue’s strong operational and cost performance.”
It is understood that current director of operations Nick Cernotta will remain with FMG.
Meanwhile, chief financial officer Stephen Pearce has resigned to take up a role with Anglo American from December 31.
FMG will start a recruitment process for the CFO role.
Shares in FMG fell by 3.5% to $A4.975.
