The versatile defender can play either as a centre half or a right back and will wear the No. 27 shirt during his time at Deepdale.
Speaking of the move, Baptiste said: It'll be good to be back playing again. Obviously I know a lot about the North West so I'm really looking forward to the challenge.
"I will just give 100 per cent, I try my best. I play centre-half or right-back but wherever I play I will give my best and that's all you can do really.
"I'm getting older now so I have a bit of experience and so I can try and help the team by passing on things I have learnt."
Manager Simon Grayson was delighted to add to his defensive ranks, saying: "Alex Baptiste is another versatile player and he has got the experience of many games under his belt. I signed him for Blackpool some time ago and he has gone on to have a great career so he is another player we are delighted to have signed."