Smith, 47, made amends with Remini during an episode of her Facebook show, Red Table Talk, scheduled to air Oct. 22.
"What was really emotional about it was realizing that there was two broken little girls in us that were abandoned by their fathers and turned into fighters who clashed," Smith told People.
The Girls Trip star clashed with Remini in 2017 after the actress claimed Smith was a Scientologist. Smith said making peace with Remini reinforced the importance of being kind and open to others.
"You have to treat people with kindness because you don't know what they're going through. When she told me her story, I had so much more compassion and it reiterated the necessity to just be gentle and kind," Smith said.
"It was nice to reconnect and release ourselves from all that nonsense that doesn't matter," she added.
Remini has been an outspoken critic of Scientology since cutting ties with the church in 2013. She said in an interview with The Daily Beast in September 2017 that Smith had been a Scientologist for "a long time."
"I have studied Dianetics, and appreciate the merits of Study Tech... but I am not a Scientologist," Smith responded on Twitter. "I practice human kindness, and I believe that we each have the right to determine what we are and what we are not."
Smith shared a teaser Thursday on Twitter for the upcoming episodes of Red Table Talk that shows her embracing Remini.