Reading coach Chris Davies will join Celtic as assistant manager to Brendan Rodgers at the beginning of June.
The 31-year-old has worked with the new Parkhead boss at both Swansea City and Liverpool and now links up with him in Glasgow.
Rodgers told the club website: "I am delighted to bring Chris to Celtic - he is a magnificent coach and someone I know will make a hugely positive contribution to the club.
“He is ready and prepared for the challenge at Celtic and I know that Chris, like myself, can’t wait to get going next season. He has worked with me previously, he is someone I know and trust and he will be a great addition to my team and to the club.”