Radcliffe, who played boy wizard Potter in the wildly successful film adaptations of Rowling's best-selling books, has found himself at odds with Rowling on the thorny issue of gender identity.
Rowling has faced accusations of transphobia for her stance emphasizing biological sex over gender identity, while Radcliffe has long campaigned for LGBTQ groups that defend the rights of trans women.
"It makes me really sad, ultimately," Radcliffe told the Atlantic, in an interview published this week.
"Because I do look at the person that I met, the times that we met, and the books that she wrote, and the world that she created, and all of that is to me so deeply empathic."
The issue of gender identity has become a polarizing political debate in many countries, including Rowling's native Scotland, and in the United States, where Radcliffe is currently performing in a Broadway play.
Rowling has been at the forefront, arguing that transgender rights endanger women. She has pointed to claims that transgender women entering female-designated changing rooms, toilets or prisons causes harm.
In 2020, Radcliffe -- a longtime supporter of the Trevor Project, an LGBTQ youth suicide-prevention hotline -- responded to some of Rowling's comments on the matter with a statement saying "Transgender women are women."
The public split was pounced upon by the British press, not least as the wildly successful Potter franchise had been embraced by children across the board.
"A lot of people found some solace in those books and films who were dealing with feeling closeted or rejected by their family or living with a secret," said Radcliffe.
British media tried to portray Radcliffe and co-stars Emma Watson and Rupert Grint as "ungrateful brats," he told the interviewer.
Last month, Rowling appeared to hit out at the film's actors once again, responding to a comment on social media suggesting she would forgive Radcliffe and Watson if they apologized.
"Celebs who cozied up to a movement intent on eroding women's hard-won rights and who used their platforms to cheer on the transitioning of minors can save their apologies for traumatized detransitioners and vulnerable women reliant on single sex spaces," wrote Rowling.
Asked to respond by the Atlantic, Radcliffe said: "I will continue to support the rights of all LGBTQ people, and have no further comment than that."
Radcliffe, who said he has had no direct contact with Rowling throughout the controversy, also acknowledged that his fame and success would likely never have happened if she had not created the Potter franchise.
"But that doesn't mean that you owe the things you truly believe to someone else for your entire life," he said.
