Notts County manager Kevin Nolan has appointed Richard Thomas as his assistant at Meadow Lane.
Nolan worked with Thomas during his time as manager of the Os and is delighted to have renewed acquaintances with his former colleague.
The manager said: "Richard is someone I know very well and I'm delighted he has agreed to come in alongside me.
"He is an excellent coach who enjoyed a lot of success in his previous role at Orient.
"Having Richard on board will be a massive help to me and he adds to what is already an excellent backroom staff."
Thomas left the Os earlier this week after guiding their Under 18s to the league title this season - wrapping up the honour before Christmas.
He also oversaw a memorable run in the prestigious FA Youth Cup as Orient reached the third round before succumbing to Leicester City.
And the new assistant manager, who aided the development of players like Moses Odubajo and Scott Kashket while at Brisbane Road, is looking forward to the latest chapter in his coaching career.
He said: "I'd like to thank Kevin and the chairman for giving me this opportunity so soon after leaving my previous job.
"It's an exciting time to be joining Notts County and I'm looking forward to helping Kevin and the chairman achieve their ambitions."
Mark Crossley will remain part of the club's coaching set-up.