Head coach Graham Potter is leaving the club after deciding to join Chelsea.
Also departing are his assistant Billy Reid, first-team coaches Bjorn Hamberg and Bruno, goalkeeping coach Ben Roberts and assistant head of recruitment Kyle Macaulay.
Under-21 coach Andrew Crofts will take on the role of Albion’s interim head coach, supported by his assistant Shannon Ruth, set-play coach Nick Stanley, Adam Lallana and assistant goalkeeping coach Jack Stern.
Chairman Tony Bloom said, “I am very disappointed that Graham will be leaving us. He has done exceptionally well over the past three-and-a-bit seasons, he is an exceptional head coach and an exceptional person. He will be hugely missed at our football club.
"He leaves an excellent legacy for his successor with the club in its highest ever position, and on the back of leading us to our highest finish in the club’s history last season.
“I would like to thank Graham, Billy, Bjorn, Bruno, Ben and Kyle for their work here, and wish them all the very best for the future.
“While our attention is now on appointing Graham’s successor as head coach our immediate focus, of course, is on Saturday’s game at Bournemouth and supporting Andrew Crofts as interim head coach.”
Technical director David Weir added, “I would like to thank Graham and all his staff for everything they’ve done. They have been a pleasure to work with throughout my time at the club. Graham has done a superb job for us and I wish him well for the future.
“However, we need to move on quickly and the main priority now is to give Crofty all the support he needs in preparing the players for the game at Bournemouth this weekend.
“He took training today and will take the team for the game. Simultaneously, we will start work on recruiting a new head coach, and after the weekend we have period of time to do that.”
Deputy chairman Paul Barber added, “Tony, David and I have already begun work to replace Graham and to secure the very best candidate for the club.
"I have no doubt there will be unprecedented interest in the job, not least because of the excellent work done by Graham but also because of the footballing infrastructure in place at our club.
“I am hugely disappointed to be losing our coaching team, particularly at this time, but I too would like to take this opportunity to thank Graham, Billy, Bjorn, Bruno, Ben and Kyle for their services and wish them well for the future. It has been a pleasure working with all of them.”