Dawn French claims that racists tried to burn down the home where she lived with Lenny Henry as they slept in bed.
The 56-year-old star did not specify where the arsonists struck but the couple lived in a grade II-listed, £2.3-million mansion overlooking Readymoney Cove in Fowey, Cornwall.
Speaking to BBC Radio 4's Front Row show about a solo show about her life, Thirty Million Minutes, she said the couple had to endure racist abuse during their 25 year marriage. Of the arson attack she said: "It was massively shocking to me. Someone put an oily rag through our front door and tried to burn us down. Luckily I woke up and smelt it, otherwise I'm not sure we would be here."
Dawn, who has a daughter Billie, 23, with Lenny, 55, says racist attitudes have not changed in 30 years.
Ukip candidate William Henwood was forced to resign from the party last month after he suggested Lenny Henry should emigrate to a "black country".
She said her ex-husband experienced racism by stealth and added: "It's the little snidey comments or things people think it is OK to say, a kind of gradual erosion that I find particularly dangerous."
The pair, who split in 2010, have previously spoken about how the Ku Klux Klan smeared excrement on their front door and doorstep and daubed graffiti on their walls.
She said she would not be discussing her new husband, charity boss Mark Bignell, 51, in her stage show.
Commenting on her body image, Dawn, who has seen her weight fluctuate in recent years, said: "You are just never allowed to be anything other than a fat woman."