Sophie Turner, 23, looked incredible as she walked around hand-in-hand with her beau in the sun-drenched location.
The Game of Thrones actress displayed her slender curves in the plunging swimsuit, which gave a glimpse of her cleavage.
The black one-piece also put her lean pins on show and she drew attention to her waist by accessorising with a thin belt.
Sophie kept her blonde tresses in a messy bun and matched her look with a pair of dark shades.
Her fiancé, Joe, 29, was also dressed for a day soaking up the sun as he wore a pair of blue swimming shorts.
The Jonas Brothers singer teamed the garment with a white top and round-framed sunglasses.
The pair were seen in Miami with Joe’s brother Nick Jonas and his new wife Priyanka Chopra.
Sophie has appeared as Sansa Stark in Game of Thrones since it first debuted back in 2011.
Ahead of the eighth and final season, Sophie admitted biding farewell to the strong red-headed character was all too much.
In an interview with British Vogue, the British actress revealed it felt like she had to grieve for Sansa.
She spilled about the last day of filming: “I couldn’t control myself I cried for hours and hours once it wrapped.
“It was like leaving behind a character that I’ve grown up with. It’s almost like a death.”
Sophie spoke to the publication alongside her co-stars Maisie Williams (who plays Arya Stark), Lena Headey (Cersei Lannister) and Gwendoline Christie (Brienne of Tarth).
Maisie divulged details about the upcoming fight scene in the eighth and final season, which took 55 nights to film.
The 22-year-old star said nothing could have prepared them to shoot the gruelling scenes.
“All the training in the world couldn’t have prepared me for the amount of stamina you needed for these night shoots,” she said.
“It gets to the point where it’s four o’clock in the morning and you’re looking around like, ‘This is ridiculous. What are we doing?’”
The Game of Thrones season eight trailer was released earlier this month.
The clip teased the final battle against the White Walkers in an extremely highly-anticipated finale.
Game of Thrones season 8 returns April 14 on HBO in the US, and the next day on Sky Atlantic in the UK.
