O'Donnell is the first signing by the Celtic manager, Tommy Burns, since he took over in July. 'I have taken my time to make sure my first major signing is the right one for Celtic,' Burns said. 'I am delighted that Phil has agreed to join at such an exciting time for the club.'
O'Donnell said: 'It's a great honour to sign for a club with Celtic's proud history. I look forward to working with a manager of Tommy Burns' ability and with the many top class players at the club. My aim is success for Celtic. I could not be prouder or happier.'
O'Donnell may make his debut for Celtic when they make the short journey to Firhill to meet Partick Thistle today.
Basile Boli, the Rangers defender, is staying at Ibrox after clear- the-air talks with the Rangers manager, Walter Smith. But he is troubled by a hamstring strain before tomorrow's game against Hearts at Ibrox. Smith says he will also check on the psychological effects of Boli's troubled week before deciding whether he plays.
Hearts will check on Craig Levein's fitness before deciding on their line-up. The Scotland defender came off during the 2-0 European Championship victory over Finland in Helsinki on Wednesday with a thigh strain.
The Aberdeen manager, Willie Miller, was waiting to check on his four Scotland internationals - Brian Irvine, Stewart McKimmie, Eoin Jess and Duncan Shearer - before today's visit to Hibernian.
The defender, Gary Smith, came through a reserve game against Hibernian on Thursday along with Joe Miller, Peter Hetherston and David Winnie.