The pregnant actress was practically glowing as she cozied up to her film producer husband while aboard a yacht in Sardinia ... an Italian island in the Mediterranean Sea.

Margot was unafraid to put her growing baby bump on full display ... wearing a chic black tube top and matching skirt -- covering up slightly with an oversized white button-down shirt.

Margot and Tom were certainly in good company ... as they disembarked the yacht alongside Bradley and Gigi, who joined them for dinner at local hotspot Lo Scoglio -- known for its scenic views.

Margot was practically on cloud nine during the outing, sharing a sweet smooch with her hubby and chatting it up with Gigi and others in their party.

The actress' baby bump has been her favorite accessory as of late, regularly putting it front and center in a number of stylish looks.

In fact, earlier in her Italian getaway, Margot hit the island with Tom ... where she wore a white blouse that was barely buttoned and gave everyone a clear look at her belly.

Margot donned a similar look while in Lake Como, Italy back in July ... showing she's proud to be a mother-to-be.

As for Gigi and Bradley ... they've certainly become a more public couple since first linking up last fall. The pair hasn't been shy about flaunting their love while vacationing with the actor's 7-year-old daughter Lea De Seine.

The twosome also made an appearance at Taylor Swift's Rhode Island residence, where an A-list group got together recently to ring in Blake Lively's birthday.