The 'Woman On A Mission' singer has previously admitted she gets anxious before every performance, but said she got even more nervous than ever ahead of taking to the iconic main stage at Glastonbury.
She told BANG Showbiz: "I love festivals but you never know what you're going to get.
"When I did Glastonbury - which was quite scary really - I almost weed my pants."
Gabriella said the reception she gets is a huge shock to her sometimes, however, and her most memorable performance to date was when she played Scotland's T In The Park festival.
She explained: "I loved T In The Park - that was the first time I played a tent and it was full. I had a peek before I went on and there was no one there, I thought that it was just like a normal gig, like I used to play in the pub.
"But then I went onstage and the tent was full, and that was pretty cool. That was the first time I'd really experienced that and it was an amazing feeling."
Gabriella Cilmi has opened nominations for the vinspired national awards which celebrate and recognise young volunteers for the inspirational work they do, and gave a masterclass to a group of volunteers to thank them for their efforts earlier this week.
For more information or to nominate someone visit www.vinspired.com