The New York Post said Remini decided to leave Scientology after she was reprimanded and interrogated by church officials for questioning and objecting to many common practices within the institution.
Remini confirmed in a statement to UsMagazine.com Thursday she has left Scientology.
"I wish to share my sincere and heartfelt appreciation for the overwhelming positive response I have received from the media, my colleagues and from fans around the world," Remini said. "I am truly grateful and thankful for all your support."
"The church respects the privacy of parishioners and has no comment about any individual church member," a Scientology representative told UsMagazine.com when asked to comment on the story about Remini.
The 43-year-old actress is best known for her roles in the sitcoms "The King of Queens" and "Saved By the Bell." She also is a former co-host of "The Talk."
She has said in the past she was a follower of the faith for more than 20 years.