The 37-year-old singer said that the feeling has only got worse as he has got older, but vowed to find a way to tackle it before the Progress tour kicks off on May 27.
He told the The Mirror, 'I get tremendous stage-fright that's getting in the way of me enjoying it.
'It's terrifying. I want to find a way around it. I will do. And it gets stronger as you get older and it scared me - really scared me.'
But a tour insider told the newspaper they are confident that Robbie will overcome his fear.
'This is a huge, huge tour - the biggest Rob has been on for years. Of course there are concerns he may find it hard to take,' said the source.
'But all the signs are incredibly positive. Being on stage with four other people is a huge psychological boost for starters and Robbie has taken great solace in that.'
And band-mate Jason Orange, who also suffers mild panic attacks before going on stage, said that he will help Rob with a few deep-breathing exercises.
'Rob and I will help each other out. We share a lot of things and stage-fright is one of them,' he said.