They have sold two million records and had ten Top Ten hits. Now the fivesome are embarking on their first arena tour, All Fired Up*.
Here, Frankie Sandford, 22, Vanessa White, 22, Una Healy, 30, Mollie King, 24, and Rochelle Wiseman, 22, speak about their struggle to the top. Frankie also talks for the first time about her rumoured stint in rehab, which turned out to be a stay in hospital.
HAPPY go lucky, that's my attitude to life.
Criticism doesn't even register any more.
It goes in one ear and out the other. I go home and me and my boyfriend Marvin (Humes, from JLS) shut the door on it all.
We haven't risen to the pressure of both being in a showbiz couple. I think that's important. We just do normal things.
We've been living together for a while now and it's nice. No matter how crazy it gets, you know you have a base to go to together.
Marv hates it when I put make-up on on days off. Sometimes he says: "You've come home as a Saturday, get it off!" And when I take the make-up off, he says: "Oh, there she is, that's Rochelle."
But I do feel better with a bit of slap on, even if I'm just going to Tesco.Pure glass ... The Saturdays with The Sun's Lia NichollsDAVE HOGAN
I'M a real worrier. I don't know if this is anything to do with it, but I'm really OCD.
When I'm learning routines with the girls, I have to go on stage knowing everything. They're like: "Mollie, stop!" I need every dance move implanted in my brain. I need to know exactly how they want it.
At home, I have to go round the whole flat and check everything is off and just so. I check everything. It's awful, it slows me down.
My boyfriend (model David Gandy) is very romantic. He is old school. He holds doors open, buys presents, that sort of thing. I like that.
When you see Girls Aloud at the beginning and then again at the end, they're just wow. They look so untouchable. I think: "When will we look like that?" But it's happening now, with this tour ? and I feel like we deserve it too.
ALTHOUGH I'm six months pregnant, there's only one song where I leave the stage during the tour.
It's not that I can't do it, it's because it would be inappropriate for me to do it, grinding along with the dancers. It's just too sexual.
The boys were also like: "We don't want to look like the one who knocked you up!" So that's when I take my little rest.
I trust Ben (Foden, her rugby player boyfriend) completely. It was hard when he was in New Zealand at the Rugby World Cup but that was because people were just finding out that I was pregnant and so I felt a bit alone.
Ben scored a try and he did the little gesture of the baby, by rocking his arms. That was lovely. I knew he was out there doing his best for him, me and the baby.
No way will I quit the band after the baby. I'll be back as soon as I can.
I'M quieter when it's all of us together. But I can go from one extreme to the other.
Sometimes, and mostly in public, I'm really quiet and don't say a peep. But then I turn into the loudest person in the room.
Sometimes you can't get me to shut up.
I wouldn't choose to go into town for a night out, I'd much rather go to the local pub. If I go out for a tear-up, I like to go to places where I can have a lot of fun but nobody will recognise me.
I always end up in east London for some reason and then have a drink-up at my house afterwards. I do love a house party.
We finish the tour in Ireland and it's there where we're going to go mental. Well, I am.
The last time we were there, I couldn't tell you a thing about the party afterwards.
At the moment I'm like, wait, wait, enjoy the tour and when it finishes I can explode!
I WAS hospitalised, it wasn't rehab.
I don't think there's anything wrong with rehab. It takes a lot of courage to enter facilities to try to beat any addiction or overcome issues, but mine is a medical condition.
I will talk about it in detail one day soon, for the sake of my fans, as they want to know. But I will say it wasn't alcohol, drugs or an eating disorder. And the dark days are now behind me. My family, friends and boyfriend Wayne (Bridge, the Man City footballer) have been wonderful.
Wayne does a lot of travelling. We can't be too spontaneous, it has to be regimented because of our schedules. We make it work. What I think is nice about the band is that we built ourselves up from the bottom.
We didn't get our break from X Factor. We weren't a household name right away. We've grafted hard.