"[Happy Father's Day] to my honey [Angelo Pagan]," the Kevin Can Wait star wrote. "You have been the daddy to our daughter that I wish I had. Thank you for showing her what love is."
Remini included a photo of Pagan holding their daughter, Sofia, who celebrated her birthday on Saturday. Remini celebrated her own birthday on Friday.
The 48-year-old actress doesn't have a close relationship with her father, George Remini, revealing last year that the two had a strained relationship after he abandoned her family growing up.
"My real dad left his wife and young daughters with no care, no child support & was physically and mentally abusive to my sisters. Now what?" she told a fan in September 2017.
My real dad left his wife and young daughters with no care, no child support & was physically and mentally abusive to my sisters. Now what?— Leah Remini (@LeahRemini) September 13, 2017
Last year, Scientology enlisted George to appear in a video denouncing Remini's A&E series, Leah Remini: Scientology and the Aftermath after the series was renewed for a second season. Remini previously wrote about her father, who is not a Scientologist, in her book Troublemaker: Surviving Hollywood and Scientology. In the book, she wrote, "My dad sold cocaine (and committed various other crimes), and then served time at Rikers Island," reports Tony Ortega.
In one of the interview clips George recorded for Scientology, he claims Remini abandoned him and refused to help him pay for cancer treatment. In another clip, George sat with his wife, 37-year-old Dana Connaughton, who claims Remini "doesn't care about her own family." They point out that Remini did not help pay for half-sister Stephanie's cancer treatment before her death in 2013.
"What was the outcome of the first series where she reached out to help somebody? I mean does this guy that she drives around with have an answer? No," George said in the videos. "Is he like up free and smiles? He used to be an enforcer for Scientology and they threw him out. So what are you talking about? To me it is like a double negative. You are talking about Scientology and all the things that were done that you did."
The videos were also posted on Leah Remini Aftermath: After Money, a site Scientology created to discredit Remini's series.
Scientology's efforts to end the Emmy-winning series have not worked, since A&E is already working on a third season. Remini, who left Scientology in 2013, said the new season will also look at other cults. She is also working on a special about Jehovah's Witnesses.
Last week, Remini signed on to star in a Fox pilot where she will play a lesbian with conservative politics. She starred on CBS' Kevin Can Wait with her King of Queens co-star Kevin James, although the series was cancelled in May.
Remini also stars in Jennifer Lopez's Second Act, which opens on Nov. 21.