But he has lost arguments with former Stonewall trustee Simon Blake and drag artist Crystal, also known as Colin Seymour.
Fox, 45, has been sued by Thorp, Mr Blake and Crystal over an online row in October 2020.
Judges have been told he referred to the three people as “paedophiles” on Twitter, now known as X.
Fox has counter-sued the trio over tweets accusing him of racism.
No final rulings have been made but a High Court judge had given decisions on a number of preliminary issues, including the “natural and ordinary” meanings of tweets.
Mr Justice Nicklin had found that Fox’s tweets were factual statements that would have been understood to mean each of the three “was a paedophile…”.
He found that tweets sent to Fox were statements of opinion.
Fox had appealed against decisions made by Mr Justice Nicklin.
Three appeal judges considered Fox’s challenges against preliminary decisions by Mr Justice Nicklin at a recent Court of Appeal hearing in London.
My acting career was destroyed by false allegations of racism. As a Christian I believe all are created equal. But I object to Critical Race Theory – a racist teaching that unfairly says white people are inherently racist. The key point in my defamation cases.
— Laurence Fox (@LozzaFox) August 25, 2023
Lady Justice Nicola Davies, Lord Justice Arnold and Lord Justice Warby on Friday upheld one challenge by Fox – relating to the meaning of a tweet he posted about Thorp.
They said Mr Justice Nicklin was “wrong” to find that the “natural and ordinary meaning” of that tweet was that “Ms Thorp was a paedophile”.
In a written ruling, Lord Justice Warby said Fox’s tweet about Thorp “did of course include the word ‘paedophile’.”
But he said he was “satisfied that the ordinary reasonable reader of that tweet would not have taken the word literally”.
He added: “It would seem to follow that (Thorp’s) claim should be dismissed.”
Lord Justice Arnold and Lady Justice Nicola Davies agreed.
The three appeal judges dismissed other challenges by Fox relating to Mr Justice Nicklin’s findings about the meanings of tweets he sent about Mr Blake and Crystal.
They also dismissed Fox’s challenge against Mr Justice Nicklin’s findings “in respect of” tweets sent by Thorp, Mr Blake and Crystal.
Lord Justice Warby said Mr Fox, who founded the Reclaim Party and unsuccessfully stood as a candidate in a London mayoral election, was “perhaps best known” for his portrayal of the character Hathaway in the ITV drama, Lewis.
He said Mr Blake was a trustee of Stonewall until late June 2021; Mr Seymour was an entertainer who had appeared in various television programmes, including Ru Paul’s Drag Race UK; and Ms Thorp had appeared in Coronation Street, and other television programmes.
All four were active on Twitter – now known as X, Lord Justice Warby said.
The online row following a tweet Mr Fox posted in reaction to tweets that supermarket chain Sainsbury’s had posted about its celebration of “Black History Month”, he said.
“On 4 October 2020 three individuals posted tweets about (Mr Fox) which used the word ‘racist’,” said Lord Justice Warby in Friday’s appeal ruling.
“He responded by tweeting about each of them using the word ‘paedophile’.
“They sued him for libel. He counterclaimed.
“There was a trial of preliminary issues before Mr Justice Nicklin.
“This is an appeal against decisions he made on three of those issues: the natural and ordinary meanings of the tweets complained of; whether they were statements of fact or opinion; and, in the case of (Mr Fox’s) tweets, whether they were defamatory at common law.
“I would dismiss Mr Fox’s appeal against the judge’s findings in respect of the claimants’ (Mr Blake, Mr Seymour and Ms Thorp) tweets.
“I would also dismiss Mr Fox’s appeal against the judge’s findings in respect of his own tweets in response to those of Mr Blake and Mr Seymour.
“ I would, however, allow Mr Fox’s appeal against the judge’s findings about his response to Ms Thorp’s tweet.
“It would seem to follow that her claim should be dismissed.”