The 22-year-old former England youth international has made 100 senior appearances in his career to date.
Bayliss originally came through the ranks at Coventry City – under the watchful eye of Latics’ Head of Academy Gregor Rioch in his early days – before joining Preston in 2019 in a deal worth £1.2million.
He has found appearances in the North End first team hard to come by, making just 10 starts in all competitions.
Bayliss came off the bench against Morecambe in midweek in the Carabao Cup and got some game time towards the end of last season.
The young midfielder will look to kick-start his career at the DW Stadium.
He said: “I’m buzzing and I’m really happy to be here,” he said. "I played here in pre-season and Wigan are a good side.
"I like the way they play, and the way the manager talks and what he wants from me and what I can bring to the team because that was massive to me.
"There are some massive teams in this league, there’s no doubt about it, but I’m coming to one of the biggest clubs in the league.
"The manager wants to get promoted, and that’s why I’m here.
“I’m always ready to go. I love playing football and that’s what I want to do.
"If I’m involved this week, or need to wait a week, that’s fine, but I’ll be ready and raring to go when the manager throws me in!”
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