Helen Mirren has responded to fans after they confused her for Keanu Reeves’ new girlfriend Alexandra GrantCredit: Getty – Contributor

Alexandra smiled adoringly at the Bill and Ted star as they posed on the red carpet at a film bash in LA.

The artist, who wore her grey hair tied back in a bun and long navy beaded gown for the event, resembled Oscar winner Helen, and the internet went wild after mistaking the pair.

Responding to the social media storm last night, the 74-year-old British actress told ET at the New York premiere of her movie The Good Liar: “I saw that.

“That was very flattering on me, you know, because she’s obviously lovely.”

Keanu confirmed his romance with artist Alexandra on SundayCredit: Getty – Contributor

Helen, who has known Reeves since he worked with her director husband Taylor Hackford on 1997 horror thriller The Devil’s Advocate, had nothing but love for the new couple.

She added: “I do know Keanu very well. He did a film with my husband and he is just the most adorable, lovely person. So she’s a lucky girl and I’m sure that he’s a lucky boy.”

Flummoxed fans quickly took to social media following the Mirren mix-up.

One tweeted: “I wasn’t wearing my glasses at first and I legit thought he was dating Helen Mirren which I also would have been here for.”

The 74-year-old said the comparison was ‘very flattering on me, you know, because she’s obviously lovely’Credit: Getty – Contributor

Fans couldn’t believe their resemblance on social mediaCredit: Twitter

Another peend: “I just realised Keanu Reeves’ girlfriend isn’t in fact Helen Mirren, so I’m feeling devastated right now, I was very heavily emotionally invested in that couple.”

While a third added: “Keanu Reeves is dating a woman my age who kinda looks like Helen Mirren and I have never been more attracted to him.”

Keanu and Alexandra’s appearance confirmed rumours they are a couple, after being spotted last month walking arm in arm as they left a sushi bar in West Hollywood.

The A-lister was previously linked to Amanda De Cadenet, Sandra Bullock and Claire Forlani but never made a public statement on nay of his relationships.

For much of the 90s, his girlfriend was actress Jennifer Syme.

Last month, they were spotted leaving a sushi bar in West HollywoodCredit: Getty – Contributor

They tragically lost their baby daughter Ava after she was stillborn prematurely, a month early.

In 2001, Syme drove her 1999 Jeep Grand Cherokee into a row of parked cars in Los Angeles; she died instantly aged 28.

Keanu has enjoyed a resurgence in his professional career since the success of John Wick and has his plate full with projects, including the highly anticipated fourth Matrix film.