The 31-year-old, who is not allowed to face the Reds at Oakwell on Saturday, has signed an 18-month deal and is looking forward to being involved against Doncaster next weekend.
He told Blackpool's official website: "I'm delighted. It's a big club and it's absolutely fantastic that I've finally signed.
"A few of my mates are big Blackpool fans but I've not told them yet so we'll see how that goes down.
"I'm going to bring plenty of enthusiasm and quite a bit of experience now that I'm getting on, but I've not lost my legs or appetite for the game."
A brief statement on www.barnsleyfc.co.uk said: "Barnsley Football Club would like to wish David the best of luck in his future career."
- Sports & Recreation