Nardiello saved the Reds from relegation last season with seven goals in the last five league matches. His overall Reds record was 108 appearances and scored 34 goals.
Reds boss Simon Davey told www.barnsleyfc.co.uk:
"We are delighted to bring Daniel back to the Club.
"Daniel worked with us as a staff last season and excelled in the games he played. Daniel will make us more of a threat at a time when we need goals".
Daniel Nardiello has also spoken to the Official Website:
"I am delighted that the manager and chairman here have given me a second chance and I just want to repay them by scoring goals. I know I have a lot to prove to some people at Barnsley but I cannot wait to get going here again.
"I am delighted to have this second chance and want to make the most of it. I am looking forward to coming back and pulling on a Barnsley shirt again.
"I don't know why things have not happened at Queens Park Rangers and to be honest I do regret going there from a footballing point of view. I picked up an injury at the start of the season and the change of manager has not helped me. I just want to play football and score goals.
"It has been a good experience for me to try something else but with hindsight maybe I made the wrong choice in the summer. I just want to play. Barnsley have given me a second chance now and I am determined to repay that with goals.
"It was a very tough decision in summer and I know it upset a lot of people. Some supporters will not be happy to see me back but I am determined to prove them all wrong by scoring goals. I am here to work hard and score as many goals as I can. I cannot wait to get going.
"I have spent the last few weeks training as hard as I possibly could and have done a lot of running work. I am fit and raring to get back on the pitch.
"Hopefully I will be able to play at Southend this Friday. We did very well there last season in a big relegation battle. I managed to score twice that day and it was a great feeling and a great result.
"Coming back to Barnsley is brilliant and this is the only place I want to play my football now. I am delighted to be back".
Scarborough Tyke's Verdict: Now I always thought Danny was a decent player. Lacked the work rate and only really seemed to pop up with the goals when it mattered, not all the time like strikers should. But I'm willing to give him another chance. If he grafts and scores goals then all will be forgiven, until then, I'm still sceptical about his return.