Teague is the third member of the Eagles' coaching staff to step down after senior coach John Worsfold and strategy and innovations coach Phillip Walsh both ended their associations with the club last week.
The former North Melbourne and Carlton defender has spent the past three seasons in Perth as the Eagles' defensive coach but is planning to return to Victoria after recently becoming a father.
"I have really enjoyed my time at West Coast, but it is time to move on," Teague told the Eagles' website.
"With the decision around the appointment of the senior coach to replace John likely to take up to a month, it’s a good time to look at other opportunities and challenges.
"I have learnt a lot in the last three years, particularly from John and Phillip Walsh, and it has been a great experience, but it is time to seek new challenges and look forward to another opportunity in the football industry to continue for my coaching development, and help another team improve.
"I would like to thank John, Alan Cransberg and Trevor Nisbett for the opportunity they gave me and wish the club the best in the future."
