The 29 year old centre back will join up with Gerhard Struber's side as they bid to escape the Championship relegation zone.
Sollbauer has signed for an undisclosed fee and links up with former team-mate Marcel Ritzmaier as well as Germany Under-20 international Kilian Ludewig at Oakwell.
Struber said: “I know a lot about Michael and he will be great for the team. He is exactly the player we need. He has been captain at Wolfsberger AC for a long time and has plenty of first team experience at a good level.
“It was important for me to have experience and to add to our defence in this window. I am very happy that Michael is here in Barnsley and I know he will be a positive impact and help us over the next weeks.”
Sollbauer has a wealth of experience playing for the Austrian side in the Europa League against the likes of AS Roma and Borussia Monchengladbach.