Newton’s 16-year-old daughter Ripley used the word in Johnson’s face after she spotted him at a showing of Harry Potter and the Cursed Child.
Recalling the encounter, Newton told the Sunday Times magazine: “She went over to say ‘Hello Mr Johnson my name is Ripley and I just wanted to tell you you’re a c***. I hope you enjoy the show’.”
Newton said “I’m so proud of her” before adding: “It’s my New Year’s resolution to not use that word in a derogatory manner.”
Ripley was hailed as “amazing” and her quip the “anecdote of the year”.
Another praised Newton for “raising good children”.
One user tweeted: “Today’s hero is Thandie Newton’s daughter.”
Another posted: “Well, Thandie Newton’s 16-year-old daughter sounds AMAZING.”
Newton also opened up about her struggle to find roles in Britain as the trend for period dramas “makes it slim pickings for people of colour”.
The Crash actress said: “I love being here, but I can't work, because I can't do Downton Abbey, can't be in Victoria, can't be in Call The Midwife - well, I could, but I don't want to play someone who's being racially abused.
“I'm not interested in that, don't want to do it...there just seems to be a desire for stuff about the Royal Family, stuff from the past, which is understandable, but it just makes it slim pickings for people of colour.”