He's been with Celtic since the summer when Tony Mowbray signed him for around £1.5 million from Coventry and he's been a regular in that Celtic side for the first half of this season. However, he's jumped at the opportunity to play in the Premier League and according to Laws.
On completing the signing the manager said: "He's a good defender, is a good athlete who likes to join in and get forward and he's a good passer of the ball. Hopefully he will help us tighten up the defence which we have been striving to do since day one so it's a great acquisition.
"Also with Danny's ability from set pieces - his delivery is frightening - we hope that we can embrace that with the quality we have and hopefully help us with our set plays."
Fox confirmed his delight in arriving in the Premier League. "It's somewhere I've always wanted to play and I'm glad to be here," he said. I think it's a club on the up and if I can be part of that it will be brilliant.
"It's been a bit of a mad career. I'm only 23 and I've played for a lot of clubs but hopefully I can have a long successful career here."
Danny won't be available tomorrow for the Chelsea game with the club awaiting international clearance, but he'll be at the Turf to see his new team mates in action. "I think the place will be bouncing tomorrow with Chelsea coming to town," he added. "I will be here to soak up the atmosphere and hopefully see the lads get a good result and then I can't wait for West Ham next weekend."