Carter appeared as Bellatrix Lestrange in the Harry Potter film franchise, based on the books by Rowling.
She has also appeared alongside Depp in seven films together, five of which were directed by her former partner Tim Burton.
Rowling has become a polarising figure in recent years thanks to her views on transgender rights, which have been accused by LGBT+ activists and organisations of being transphobic. The writer has denied that she is transphobic.
Speaking to The Times in a new interview, Bonham Carter said: “It’s horrendous, a load of b******s. I think [Rowling] has been hounded. It’s been taken to the extreme, the judgmentalism of people. She’s allowed her opinion, particularly if she’s suffered abuse.
“Everybody carries their own history of trauma and forms their opinions from that trauma and you have to respect where people come from and their pain. You don’t all have to agree on everything – that would be insane and boring. She’s not meaning it aggressively, she’s just saying something out of her own experience.”
Depp, meanwhile, was embroiled in a high-profile legal battle with his ex-wife, the actor Amber Heard, earlier this year.
The Pirates of the Caribbean star had sued Heard, alleging that she had defamed him in a 2018 op-ed about domestic violence published by the Washington Post. Depp claimed that the piece implied he had abused her while the pair were married.
A jury ultimately found that Heard had defamed Depp, and the Aquaman actor was ordered to pay her ex-husband $10m (£8m) in compensatory damages and $5m in punitive damages. However, the jury also ruled in favour of Heard’s countersuit, finding that one of Depp’s attorneys had defamed her by characterising her abuse allegations as a “hoax”. Heard is set to appeal the decision.
In the Times interview, Bonham Carter claimed that the court verdict had vindicated Depp, who is also godfather to her children, Billy Ray, 18, and Nell, 14.
“Oh, I think he’s completely vindicated,” she said. “I think he’s fine now. Totally fine.”
Asked if the libel case was the “pendulum of #MeToo swinging back”, Bonham Carter replied: “My view is that [Heard] got on that pendulum. That’s the problem with these things – that people will jump on the bandwagon because it’s the trend and to be the poster girl for it.”
A British court had previously ruled in favour of The Sun after the paper described Depp as a “wife-beater”, ruling that the description was “substantially true”.
Elsewhere in the interview, Bonham Carter also spoke about the 21-year age gap between herself and her current partner.
If you or someone you know is experiencing domestic abuse, you can call the 24-hour National Domestic Abuse Helpline, run by Refuge, on 0808 2000 247, or visit their website here.