The former Radio 1 DJ was joined by husband Jesse Wood at the Kensington Roof Gardens in London, where Ant & Dec were throwing a huge, celebrity-packed joint 40th birthday.
She joked on Twitter: "We went out. Tired parents."
Fearne gave birth to Honey Krissy Wood on 9 September. She and musician Jesse - who is the son of Rolling Stone Ronnie Wood - are also parents to son Rex, two.
Ant & Dec's birthday was a star-studded affair with Fearne's close friend Holly Willoughby and Celebrity Juice co-star Leigh Francis aka Keith Lemon also among the guests.
Others toasting to the Geordie pair's big day included Cheryl Fernandez-Versini, Davina McCall, Piers Morgan, Amanda Holden, Marvin Humes, Alicia Dixon, David Walliams and Emma Bunton.
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