According to reports, Geri and Russell have been on a string of low-key dates in recent weeks, after hitting it off at the Olympics closing ceremony.
Geri Halliwell was at the Olympic venue to perform a medley of hits with the Spice Girls, while Russell Brand arrived in the stadium atop a London Bus as Willy Wonka.
It's thought the pair got on like a house on fire between performances back stage stage, reportedly causing Russell to split with then-girlfriend Isabella Brewster.
Insiders say Russell Brand and Geri Halliwell's relationship is already 'very serious,' with Russell spending extra time in London just to spend time with his latest love interest.
'Things are getting very serious between them — they’re a proper couple now,' one source told the Sun. 'They had met several times in the past, but really got to know each other during the Olympics.
'People thought Russell was joking at the time, when he said he had a crush on Geri all over again, but it was true,' the insider added. 'They just clicked — they have so much in common.
'He is spending so much more time in London just to be with her.'
Another insider said of Russell and Geri's relationship: 'He ended his relationship with Isabella Brewster, and is now dating Geri properly.
'They’ve exactly the same sense of humour and are serious about clean living.'
The couple were spied indulging in a spot of sightseeing over the weekend, setting off on a private tour of Hampton Court Palace with Geri's daughter Bluebell in tow.
And onlookers said it was '100 per cent' obvious Russell and Geri were an item.
'I thought it was the most random thing ever to see Russell Brand of all people in a place like that — until my wife pointed out he was with a Spice Girl,' one told the Sun. 'They seemed like they were having a really great time, holding hands and chatting — it was 100 per cent obvious they were a couple.'
We didn't see that one coming!
What do you think of the latest celebrity romance rumours? Is Russell Brand really dating Geri Halliwell? Or is the story utter rubbish? Let us know in the comments box below…