While the 28-year-old Younger star made sure to shade her face with a big, floppy hat, she did flash some cleavage in a black-and-white close-up selfie she shared to Instagram.
On New Year's Day, Duff showed off her tan chest in a black swimsuit as she and her friend, actress Molly McQueen, shared some fruity beverages. This time it was McQueen's turn to sport killer headwear.
Duff looked even more radiant in a pic she posted on Dec. 30, showing off her flowery lei -- as well as her flawless face.
In September the mother-of-one took to Instagram to flaunt her phenomenal physique in a sexy black-and-white stripped bikini top while enjoying a beverage served inside a pineapple.
Check out the video below for a look at Duff's super-sexy poolside pic.