Nick Hammond's "excellent advice to the club over the summer" was key to Celtic naming him head of football operations, says chief executive Peter Lawwell.
The former Reading director of football and West Brom technical director joined the Scottish champions as a recruitment consultant in June.
Hammond begins his new full-time post immediately and will continue to work closely with manager Neil Lennon.
"This is a hugely important role," Lawwell said.
"And in Nick we have appointed a man who we know will deliver excellent results. His wealth of knowledge and expertise will be invaluable to Celtic going forward."
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Hammond was pivotal to Celtic's transfer dealings this summer - their 14 signings included £7m French defender Christopher Jullien and the loan return of goalkeeper Fraser Forster - and is ready to implement the findings of his review into the club's recruitment and scouting strategy.
Hammond, who initially joined on a consultancy basis after head of recruitment Lee Congerton left for Leicester City in May, is keen to build on the "good work" done so far.
"I wanted to play my part in continuing to improve the club's processes and ultimately ensure that we continue to recruit and develop the best possible players we can at Celtic," he said.
"Across the football department we will work together to ensure that we continue to meet these high standards and do all we can to play our part in bringing success to the club and our supporters.
"This was very important for me and a huge factor in deciding to move to Glasgow."
Hammond's appointment has also welcomed by Lennon, who said: "I have known Nick for some time and I know I can trust him and rely on him to produce excellent work across our football operation."