Netflix's Bridgerton has its very own 19th-century Gossip Girl, and Lady Whistledown, as she's called, is voiced by none other than the one-and-only Julie Andrews. Lady Whistledown narrates the entire series, and people know her as the omnipotent author behind the scandal sheets that circulate around town. She knows everything about everyone — and no, she doesn't turn out to be a male ghostwriter like Dan Humphrey. Eloise Bridgerton (Claudia Jessie) makes it her personal mission to unmask the mysterious lady, failing to realize that she's been so close to London's source of piping hot tea. Lady Whistledown, dear reader, turns out to be Eloise's dear friend Penelope Featherington (Nicola Coughlan).
Lady Whistledown knows all. What's special about her scandal sheets is that she doesn't just post rumors. Her stories are indeed factual and true. She even spills the tea on Marina Thompson's (Ruby Barker) secret pregnancy, a reveal with, undoubtedly, personal motives given her true identity. Bridgerton throws a couple of red herrings at us. It initially teases the idea that Lady Whistledown is Eloise, who, in Jo March fashion, is a writerly type adamant about continuing her education and living independently. When Benedict asks her if she's behind the hot gossip, Eloise denies it, and the Queen recruits Eloise to track down the author. And so, Eloise looks at everyone from servants to the women in her mother's social circle.
Eventually, Eloise narrows it down to the dressmaker Genevieve Delacroix (Kathryn Drysdale), deducing that Lady Whistledown has to be a tradesperson and a financially independent woman. Eloise has a talk with the modiste, who entertains this assumption. When Eloise learns that the Queen's people have figured out when and where Lady Whistledown drops off her articles, the headstrong Bridgerton sister creates a diversion to help Whistledown flee. And so, Lady Whistledown lives to publish another story.
Eloise later learns that Madame Delacroix spent the night of the ball with Benedict, so she couldn't have been Lady Whistledown. A flashback reveals the true identity of the hooded figure in the carriage the night of the ball: Penelope Featherington. Penelope has been a quiet observer at all of London's social events, overlooked by her friends and family. In hindsight, she's the only person who knows about Marina's condition and would share it with the world due to her feelings for Colin. Given her family's debts, Penelope's side hustle moonlighting as London's go-to gossip doesn't appear to be very lucrative, though.
In case you were wondering, Pen also turns out to be Lady Whistledown in Julia Quinn's book series. Penelope's alter ego comes to light in Quinn's fourth Bridgerton novel, Romancing Mister Bridgerton. We'll have to see if the rest of London society ever catches up with Lady Whistledown's identity on the show!