The star took to Instagram on Friday to share a photo of herself rocking a new cow-print bikini from her Jessica Simpson Collection swimwear line.
The 39-year-old fashion designer and singer paired the look with a black, sheer cover-up featuring lace embroidery and a black hat with gold embellishments.
“YEE-HAW to my final days in my 30’s,” Simpson captioned the snapshot, which featured the mom of three looking back at the camera.
The “Open Book” author’s label also shared a photograph of the star modeling the new two-piece as she posed on the beach.
“Cancer Season! ✨ 🌟💫 New summer swim is now on jessicasimpson.com! 📸 @kristingram #JessicaSimpsonStyle #JessicaSimpsonSwim,” the caption reads.
Simpson’s birthday is on July 10.
Last month, Simpson shared another photo of herself wearing a look from her collection — this time, workout shorts and a matching sports bra.
In the picture, Simpson was drenched in sweat after an early morning workout session as she flexed her leg muscles, showing off her incredibly toned calves.
“Woke up before all 3 kiddos to get my steps in and spend time with me, myself, and I. Move move move for your own mental health. 💪🏻” she captioned the photo.
Her trainer, Harley Pasternak, revealed last fall that Simpson’s fit body is the result of her dedication to a more holistic post-baby lifestyle.
Fox News’ Melissa Roberto contributed to this report