Some fans had thought that the Oscar winner was the woman who has been seen with the Matrix actor and that they were an item.
A beaming Keanu appeared hand in hand with artist and publishing partner Alexandra Grant at a museum gala in Los Angeles, prompting speculation that they are a couple.
Fans noted Alexandra’s resemblance to Helen, and some believed Keanu and Helen were dating, although The Queen actor has been married for decades to director Taylor Hackford.
Helen told “Entertainment Tonight” that she was aware of the chatter.
“That was very flattering on me, you know, because she’s obviously lovely,” she said at the New York City premiere of The Good Liar.
Helen, whose husband directed Keanu in 1997′s The Devil’s Advocate, said she knows the star “very well.”
“He is just the most adorable, lovely person. So she’s a lucky girl and I’m sure that he’s a lucky boy.”
The 55-year-old John Wick actor has always kept his private life just that, and previously told Esquire: “I think actors and actresses are maybe a little more private than other celebrities.
“I don’t know. I’m a pretty private person. But I don’t have anything to tweet, or say, or anything.”
Keanu has previously been romantically linked to Sandra Bullock and Amanda De Cadenet.
In 1999, he and his girlfriend Jennifer Syme lost their daughter in the final stages of the pregnancy. Just 18 months later, Jennifer was killed in a car accident.