The 18-year-old defender has signed a loan deal that will see him spend the coming season at the club.
James is a multi-treble winner with the Chelsea youth team, while he also won the 2018 Academy Player of the Year award.
The England youth international is set to become a first team member at Wigan, which is an opportunity he would not have gotten at Chelsea.
"There were some different options available," James said to Wigan's official website.
"I chose to come to Wigan Athletic because it's a great club and I'm looking forward to playing my part.
"I've been watching the team play for a while now and I was very impressed by what the team achieved last season in winning League One.
"I really like the way the manager has the boys playing football, for any young player it's an attractive style to want to fit into. I like the way the gaffer works here and he's been very good with me through the whole process of signing on loan."