She's famed for playing the sexy Betty Draper on AMC's hit show Mad Men, but January Jones proved that her real life persona is just as seductive judging by her Instagram profile.

The 39-year-old actress from South Dakota wowed her 506K followers with her latest holiday snaps of herself in a vintage style high-waisted designer bikini by Lisa Marie Fernadez, featuring cute retro buttons.

January – who has starred as Melissa Chartres in the Fox series The Last Man on Earth since 2015 – boasted a shapely and toned physique with a plentiful cleavage in the stylish shots.

She styled the fashion-forward two piece with a statement gold necklace, a straw hat and oversized shades, and while one snap showed her peering into the camera up close, the second one saw her looking over shoulder while poking her tongue out as she displayed her behind.

Fans excitably commented on the raunchy snaps in their droves, as January seldom posts bikini shots.

One follower commented: "Yessss!!!!! She's got such a beautiful body and should show it off more!"

Second said: "The only January that never give you the blues "

The second pictured garnered many comments on January's behind, with another writing: "That ass, that attitude!!"

Someone else added: "Nice ass. (Can I say that on Instagram?)"

January received two Golden Globe nominations and one Emmy nomination for her work on the hugely popular Mad Men. Outside of the acting world, January has a son named Xander Dane Jones and in 2009 joined Oceana as a celebrity spokesperson, working to save endangered sharks.