The 'Lucky Day' singer was the only member of the on hiatus girl group to toast Kimberley's big day but made sure Cheryl Cole, Sarah Harding and Nadine Coyle weren't forgotten as she paid tribute to her pal.
Speaking at the party at the Westbury hotel in London's Mayfair district, she said: "This is on behalf of Girls Aloud. We love you babe. I remember when you were 22, and now look at you all grown and 30. Whoop.
"We're so proud of you. Me, Cheryl, Sarah and Nadine all adore you. Girls Aloud forever."
Cheryl is currently recovering from pharyngitis, and Nadine and a recently released from rehab Sarah are both in the US.
Cheryl tweeted: "Looks like a good night, Happy Birthday Kimba, more beautiful and special than ever, love you sooooooo much. (sic)"
However, Kimberley didn't appear to miss her friends too much, along with Nicola, she was joined by her boyfriend of eight years Justin Scott and plenty of celebrity friends including Denise Van Outen and the cast of the musical 'Shrek' which she is currently starring in.
Nicola wrote on twitter after the party: "I love you Kimberley. X"
Denise also took to the micro-blogging site to write about the bash: "Just got home from a fab party to celebrate my friend's 30th birthday. Had a right ol' boogie. Woo hoo!! (sic)"