January Jones says she doesn't feel a day older than 27 - and she doesn't look it either.
The star shared a snapshot from her luxury home in Los Angeles where she was soaking up the sun in a leopard print swimsuit.
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January looked a little somber but sultry in the one-piece with frilly detailing and a plunging neckline.
WATCH: January Jones slides into her incredible living room at LA home
The Mad Men actress thanked fans for her birthday wishes in the caption and wrote: "Thank you for your birthday wishes yesterday. I've always been of the theory that Age is But a Feeling. And despite a rough last wk or so I'm feeling really good, really grateful and around maybe 27 (but wiser)."
Fans were stunned to discover she had just celebrated her 44th birthday and bombarded her with compliments in the comments.
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"Forever a bombshell," wrote one, while another added: "Happy belated birthday beautiful amazing lady hope it was an awesome day," and a third gushed: "You're a jewel...LOVE ya immensely mate...hope your bday was full of lots of love, laughs & tons of fun. And age is irrelevant. Glad to hear you're in high spirits and feelin youthful....keep it silly my friend."
January thanked her fans for their birthday well-wishes
There were strings of heart emojis and others telling her she still looks like she's in her twenties and that they adored her swimwear.
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January was fortunate enough to spend the festive season with her loved ones and documented their fun antics on social media too.
January seemingly has a swimsuit for every occasion
But she also explained why her holidays were slightly stressful in a lengthy post which read: "Had a pimple in my mole that I squeezed and then my mole fell OFF and won't stop bleeding. @delta decided to fly our plane empty to Sacramento instead of full to LA right before we were about to board.
"Now stuck and waiting out a winter storm warning. My 2022 decorations are waiting for us in LA so I'm going to just sit here and burn wood for a time period.
"On the bright side my Omni is gone. Happy New Year!"
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