Carlson, who played Linda Reagan on the show, announced her departure on her Instagram page after the season eight premiere.
"My heart is full of gratitude to each of you for your generous support of me and my character for the last seven years of Blue Bloods Linda Reagan.
"I have been touched by your compassion and enthusiasm. I loved playing Linda: wife to Danny, mother to Jack and Sean, nurse and working mom. I'm proud of my contribution to building this series. I'm so grateful to CBS and the Blue Bloods cast and crew. Mostly, I am grateful to the fans who have supported me and the show. Peace, blessings and many 'love you mores' to all of you," she captioned her photo.