McNaughton worked with Dougie Freedman at Wanderers during the first half of the last campaign and, after joining on a season-long loan, he is happy to have returned to the Macron Stadium.
The 31-year-old defender told the club's official YouTube channel: "I enjoyed my spell here last season and I'm looking forward to working with the manager again, where we'll hopefully have a good go at promotion.
"I'm getting to an age where I want to be playing football and this is a good opportunity to get some games under my belt.
"I thought I would have come back once my first spell ended last year but with the new manager coming in at Cardiff, things changed pretty quickly.
"I had a decision to make over the summer and my chances of first-team football there were pretty slim. I didn't want to be sat in the stands watching games, and I'm delighted Bolton came in for me."McNaughton flew out to join the club's pre-season tour in Malmo, Sweden, once the deal was finalised and he is relishing the chance to bond with the squad ahead of a full season at the club.
He added: "Pre-season is about bonding with the new and old faces in the team and to mingle, as well as getting our fitness up.
"I played 45 minutes with Cardiff last week and I feel good. I'm probably just at a stage where I need a couple more games to get my fitness up to scratch with the others.
"Once I knew Dougie wanted to bring me back, it was an easy decision from then. The fact I'd been here and know everybody made it a lot simpler for me."