The actress, 40, has been on a lifestyle journey ever since she gave birth to her third child, a daughter named Rani with her boyfriend Danny Fujikawa, in October.
On Wednesday, Hudson showed off her enviable figure in a red bikini while posing alongside her friend and fashion stylist, Sophie Lopez, as they both sipped on summer cocktails during a June trip to Italy.
Hudson captioned the snapshot, which celebrated her close pal's birthday: "The biggest happy birthday to my partner in so many adventures! I love you babas! @sophielopez Sending love your way and wishing I was with you today!"
Many social media users couldn't help but compliment the actress on her toned physique.
"Wow! You just had a baby not too long ago, and look at those abs, Gorgeous!!!" wrote one person.
"Ummmm didn't you just have a baby?!?!" commented another.
Wrote one individual: "Holy post baby body!!!"
The "Almost Famous" star set a goal back in December to lose the baby weight when she became a celebrity ambassador for WW (formerly Weight Watchers).
"Health and wellness is my number one, and I always say what works for me doesn't work for everyone," she said during her campaign at the time.
In April, Hudson revealed she had almost achieved her goal. "I’ve done it without stressing on food or working out like crazy although I have been disciplined," she explained.
She also credits her workout routine for helping her drop weight. Hudson regularly hits the gym for yoga, pilates, spinning, and works with trainer Nicole E. Winhoffer on a mix of stretch and cardio dance routines.
"I’d like to try new workouts and eat as healthy as I can," Hudson wrote on Instagram post. "I wanna do all this and keep up milk production, raise my kids, work everyday, make time for my man, have girlfriend time and stay sane!"
Hudson is currently hard at work on her next movie, a fantasy movie called Mona Lisa And The Blood Moon, which is being shot in New Orleans.