The former "King of Queens" star appeared on the show to promote the upcoming season of "Dancing With The Stars."
With the controversy surrounding her July defection from Scientology, though, DeGeneres asked why she joined Nicole Kidman, Jerry Seinfeld and Demi Moore in breaking from the organization.
The controversial faith, which was founded by sci-fi writer L. Ron Hubbard, counts John Travolta and Tom Cruise among its members. Remini had been part of the church since she was a child.
"My mother got involved when we were very young, so it's all we ever really knew," Remini said. "But over time, my eyes opened and I could just no longer be affiliated with the organization and my family felt the same, so we left."
"How are you?" DeGeneres asked. "I hear it's different than leaving another religion, so are you OK?"
"I'm OK," Remini said. "It's hard. We lost friends that can no longer talk to us who are still in the organization."
"Now, that is a thing?" DeGeneres asked. "When you leave the church they can't talk to you and you can't talk to them?"
"Correct. And these are friends that we've had for dozens of years," Remini continued. "But I have great friends, other friends that are not in the church, that have stood by us. Our family is stronger, we're together and that's all I can ask for."
Remini said her break from the church came after she was reportedly being asked to undergo "interrogations" and "thought modification," as the church bars members from questioning leadership.
She also said that she also disagreed with church policies that allegedly force members to break ties with family members deemed "suppressive persons" if they leave the church.