Celtic have signed Willo Flood from Cardiff City for £100,000 on a two and a half year contract
The Dubliner told the club website:
"It really is a tremendous honour to sign for a club of Celtic's stature.
"I have been a fan of Celtic all my life and this is a dream come true." "This is an exciting challenge and one which I am really looking forward to."
"I will be joining a great group of players and I will be giving everything I can to make as big a contribution as possible to Celtic. "I hope to play my part in achieving more and more success for the club and its supporters."
Flood made close to 70 appearances while on loan at Dundee United and was offered a permanent deal, but he chose to join his boyhood heroes.
He told the Celtic website:
"I would like to thank Dundee United FC for all they have done for me. "I have enjoyed my time there immensely and I wish the club all the best for the future.
"My focus is now Celtic and I can't wait to get started with my new club."
Celtic manager Gordon Strachan said:
"We are delighted to welcome Willo to Celtic."
"He has had a tremendous time at Dundee United where he has shown great ability, drive and enthusiasm. We look forward to working with him."