Margot Robbie is enjoying some much-needed R&R after becoming a new mother … lighting up the beach in a tight gray bikini just months after giving birth.

The actress was down in her native Australia enjoying Easter weekend on the Gold Coast … and, the weather in the area looks beautiful — which got MR to strip down to a bikini for a dip in the ocean.

Check out the pics … Margot’s wearing a two-piece with a bit more coverage than some skimpy ensembles we’ve seen celebs wear, chatting with a pal while enjoying the afternoon sun.

While there’s not a glimpse of her kiddo in the pics, Margot’s clearly embracing her new role as “mama” … ’cause the word is written on the gold necklace wrapped around her neck.

She also shared a sweet moment with her producer husband Tom Ackerley … with her man wrapping his hands around her waist in a sweet embrace while laid out on a lounge chair.

The two new parents welcomed their first child together in the fall … a few months after Robbie revealed she had a baby bump while stepping out on vacay.

While she hasn’t talked publicly about being a mom yet, reports have said she’s loving the experience … spending a ton of time in L.A. with a little baby boy, according to People.