Dr. Montgomery is an esteemed gynecological and neonatal surgeon, who was originally introduced in season 1 as Derek Shepherd's (Patrick Dempsey) estranged wife. Walsh's character originally made her exit in season 3 for the spinoff series "Private Practice."
The actress announced the exciting news on social media by dancing to the popular "Questions I Get Asked" TikTok trend.
"It's really happening. Dr. Addison Montgomery will see you shortly," Walsh posted on Facebook.
Many beloved cast members recently returned to the latest season of "Grey's Anatomy," including Dempsey, and this news gives fans even more to look forward to.
Season 18 of "Grey's Anatomy" premieres Thursday, Sept. 30 on ABC.
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