The 21-year-old, who spent last season on loan in the National League with Eastleigh, made 41 league appearances during that spell and has signed a two-year contract at the DW Stadium after featuring for Wigan as a trialist in pre-season.
The Wales Under-21 international is in contention to make his first competitive appearance for the club when Gary Caldwell's side host Barnsley in Saturday's Carabao Cup first round.
Elsewhere at Dean Court, Wrexham, Southampton, Birmingham City, Hamburg and Genoa have all been credited with interest in striker Daniel Jebbison, according to the Bournemouth Echo.
The Canada international has impressed during pre-season, scoring twice and setting up team-mates in three of Bournemouth's five goals in a friendly win over Augsburg in Austria, and has said he wants to fight for his place at the club.
Boss Marco Rose rates the 22-year-old highly, though it remains unclear whether regular minutes will be available to him this season, with new arrival Álvaro Rodríguez, an already-established Evanilson, and the versatile pairing of Junior Kroupi and Rayan all able to operate through the middle.
"I want to stay here, play and help the team as much as I can, whether it's off the pitch, on the pitch," Jebbison told the Echo after scoring against St Pauli.
Should Bournemouth conclude that regular football will be hard to come by, interested clubs are expected to pursue a permanent deal rather than another loan, according to Sky Sports' Mark McAdam. He has twice gone out on Championship loan from Bournemouth, with a difficult stint at Watford followed by a much brighter one at Preston last season, where six goals in 40 games underlined his development.
Bournemouth signed Jebbison from Sheffield United for £1.5m in 2024 on a four-year deal, and while he has made just 21 appearances for the Cherries since, scoring three times, the club continue to regard him as one of their most promising young forwards.
Harris, meanwhile, arrives at Wigan having previously spent time on loan away from Bournemouth as he looks to kick-start his senior career in League One, with Caldwell keen to add competition at centre-back ahead of a season in which the Latics will hope to push for promotion.