The Jurassic Park star, 64, couldn't resist complimenting the blushing presenter on her clothes, nails and even her teeth during a cheeky tangent of the ITV interview.
Fans flocked to Twitter to insist the megastar was 'blatantly in love' with Holly, 36, - and claimed it looked like poor co-host Phillip Schofield wasn't even there.
Charmer Jeff kicked off the flirting while discussing his character in the new film Thor: Ragnarok.
Getting sidetracked by Holly's floral blouse, he leaned in and asked: 'What's that on your top? Are those flowers?
Looking flustered by the sudden change in subject, Holly joked: 'They're little blooms for you. Gold-Bloom.'
Jeff, who married 34-year-old Canadian dancer Emilie Livingston in 2014, gushed: 'That's so sweet.'
No doubt feeling a tad left out, Phillip interjected: 'Were you admiring her ring?
Nodding, Jeff said '...and the ring of course, her jewellery, that nail polish.'
Laughing, Holly looked down and muttered: 'You're making me feel very good this morning! Thank you.'
Still transfixed by her nails, Jeff asked: 'What colour are those?'
'They're a nude. A sort of nude,' Willoughby replied smiling.
'A kind of a nude yeah,' he agreed - before comparing her to iconic actress Faye Dunaway's role opposite Steve McQueen in a 1968 heist film.
'I was saying it reminded me of Faye Dunaway in The Thomas Crown Affair,' Goldblum said, leaving the presenters stunned.
'You have a great eye for detail!' Phillip managed eventually. 'Oh really? Sometimes. I'm like Sherlock Holmes in some ways,' Jeff replied, flashing a mischievous grin.
Holly countered: 'You'd make a good Holmes,' then burst out laughing as Jeff turned his attentions back to her.
Eye for detail: Transfixed by her nails, Jeff then asked: 'What colour are those?' 'They're a nude. A sort of nude,' Willoughby replied smiling.
Ever the charmer, the Independence Day star then gushed: 'Look at your teeth! Look at those 64 teeth staring back at me!'
Unable to control herself, Holly burst into a fit of giggles as Phillip smiled alongside her.
The teasing exchange wasn't lost on This Morning viewers, who claimed on Twitter that Jeff 'blatantly fancied' Holly and was even 'eyeing her up'.
'#JeffGoldblum was totally hitting on @hollywills lol. I like how @Schofe pointed out Holly’s rings and Jeff just said “Oh her jewellery” lol,' one wrote.
'Do you think Jeff Goldblum has a mini crush on Holly? I love it! Definitely an eye for detail! #PerfectGentleman,' another added.
Stopping the interview from just about descending into farce, the trio managed to get back onto safer ground with questions about Jeff's latest role in Thor.
But things took another light-hearted turn when Jeff talked about pretending to see things that aren't there while describing CGI filming.
Seeing an opportunity for comedy, Holly interrupted with the quip: 'That sounds like me on a Friday night!'
By EKIN KARASIN.
