Gossip Girl’s identity FINALLY revealed after five years in 100th episode. Spoiler alert!

Spotted: the Upper East Sider who has finally revealed s/he is Gossip Girl. If you don't mind a spoiler or two, read on. You know you want to!

We've been glued to Gossip Girl ever since it hit our screens five years ago, and the one question on everyone's lips through all those episodes was always: who is Gossip Girl?

The 'one and only source behind the scandalous lives of Manhattan's elite' kept us entertained with her voiceover and her sign off: 'You know you love me. Xoxo. Gossip Girl'

She always said her identity was a secret she'd never tell, but that's all changed now.

It was fitting that the person behind the gossip was revealed in the show's 100th landmark episode, which aired in the US last night.

Castmembers including Ed Westwick, Kelly Rutherford, Blake Lively, Penn Badgley, Matthew Settle and Kaylee DeFer celebrated the landmark episode with New York City Mayor Bloomberg last week.

So who is Gossip Girl? None other than villain extraordinaire Georgina Sparks! Oooh.

[See also: Liz Hurley gets up close and personal with Chace Crawford for Gossip Girl]

Gossip Girl's identity is finally revealed in the 100th episode. It's Georgina Sparks! / WENN

She was seen at her computer, signing off on her blog with the classic: 'Xoxo, Gossip Girl.'

Kristen Bell has been the voice of Gossip Girl so as not to give away the true identity to viewers.

Georgina, played by Michelle Tratchenberg, was up to her cunning ways in the episode which featured Blair Waldorf's (Leighton Meester) royal wedding to Prince Louis.

We'll tell you no more than that, as we want to keep it a surprise for when the episode airs in the UK.

Many fans weren't surprised by the revelation, as hints started back in November.

Michelle told TVLine.com at the time: "It's always amazing coming back to Gossip Girl. We're a family. Even if Georgina always tries to break it up.

"I can't say how many episodes [I'm doing]. But there will definitely be a healthy dose of Ms. Sparks, and to be a part of the 100th episode, a big milestone, is very special."

She added: "What we love about Georgina is that she can't help but be evil, even when she pretends to be good."

True that.

Why not check it out for yourself, as the 1ooth episode of Gossip Girl is available to download from iTunes now! Brand new episodes are available on iTunes every Wednesday, just one day after they air in the US and ahead of ITV2.