The 19-year-old signed for the club in February and played the rest of the season in the Championship.
Playing 16 times last term, van den Berg made a big impression, which prompted Preston's desire to secure him for this season.
Preston boss Frankie McAvoy said, per the club website: "We're absolutely delighted. We're very grateful to Liverpool for allowing him to come back here and obviously to Sepp for choosing to come back to us.
"He loved his time here last season. He's a young boy learning his trade and for me he's fitted in well with a group that made him feel welcome and a part of it.
"He came as a right centre back. He didn't get many games playing in that position, but he fitted in really well as a right back and then as a right wing back. I thought he was fantastic. I think he's done really well and we'll see how he does at right centre back.
"What he's got to try and do is go again for the second time and hopefully produce what I and the coaching staff believe that he's capable of."