The 23-year-old was previously with Borussia Dortmund’s reserve team and has also played for Alemannia Aachen.
Brewers boss Jimmy Floyd Hasselbaink told the club’s official website: “He wants to come to England, to Burton, to show what he can do and he’s very hungry. He can only get better.
“It works a little bit different in Germany. Borussia Dortmund is in a way two different teams and it’s a good standard of football he’s used to.
“We know the standards of German football and how well they do and that they are physically good.”
Thiele becomes Burton’s third summer signing following the arrival of former Stevenage defender Darius Charles and midfielder Calum Butcher from Dundee United.
Thiele added: “I’m happy to be here and I would like to give 100 per cent and I hope I can help the team.”