The Wales captain was forced off in the second half of their 9-0 win over Feyenoord earlier this month and will now undergo surgery.
"Following assessment by the club's medical team and a knee specialist, Sophie will soon undergo surgery before beginning a period of rehabilitation at the club," Chelsea said in a statement.
Ingle is the latest to join the list of high-profile WSL players to suffer an ACL injury after Chelsea forward Sam Kerr and Manchester City midfielder Jill Roord.
ACL injuries have been on the rise in women's sports and in December last year, European soccer governing body UEFA introduced a women's health expert panel to understand the rising cases of ACL injuries among women players.
The global soccer players union FIFPRO said an increased workload, travel, and insufficient rest have contributed to an increase in injuries including torn ACL among women professional players.
Chelsea will host Aston Villa in their WSL opener on Friday.