Grant is keen to get behind the camera
Grant, who was attending a screen writers' awards ceremony in London on Wednesday, was asked whether he would be a surrogate father for the child.
He said: "Absolutely not. I find that a slightly patronising invention. I'm not being a godfather."
Hurley, 36, is expecting her first baby in April with former boyfriend, movie producer Stephen Bing.
Grant said he had seen Hurley on a recent visit to Los Angeles.
"She seemed fine, very well," he said.
The former Estée Lauder model and Grant split in May 2000.
Their separation shocked the entertainment world but the pair have remained friends and still jointly run their Simian Films production company.
Grant was among a host of celebrities attending the annual Oscar Moore Screenwriting Prize ceremony in Leicester Square.
Directing
He said he was keen on moving behind the camera to direct.
"I've spent quite a long time acting now and I'm not giving it up, just broadening my horizons," said Grant.
"I'm writing a short film, but I don't really want to act in it. I'd rather direct it, that's how I feel at this stage in my life."
Grant also confirmed that he will be starring alongside Sandra Bullock in a romantic comedy next year.
Also at the ceremony was Academy Award winning director Anthony Minghella.
The man behind The English Patient and The Talented Mr Ripley said he is currently working on an adaptation of Homer's Odyssey.
Minghella said Tom Cruise had expressed interest in starring in the film, but nothing had been finalised yet.
The director said he was hoping to move away from adapting books.
"I somehow got diverted into adapting. I now want a decade of writing original work because adapting takes too long."
The ceremony at Leicester Square honoured new European screenwriting talent.
Marcus Lloyd scooped the main prize, winning the £10,000 prize for his dark thriller Cuckoo.