Lady Gaga kicked off 2018 with a make-up free, hair extension-free snap of the heavily-tattooed left side of her body wearing nothing more than a white thong bikini.

'Happy New Year!' the 31-year-old pop diva - who boasts 159.2M social media followers - tweeted Wednesday. 'To happiness. Health. Love. And to the simplicity of beautiful unforgettable nature, life.'

The six-time Grammy winner was pictured sunning herself at either her seaside Malibu mansion or in Tulum with her rumoured fiancé Christian Carino and manager Bobby Campbell. 

At 48, the CAA talent agent is 17 years older than his No. 1 client (born Stefani Germanotta), whom he popped the question to last summer - according to Us Weekly.

Carino - who has Gaga tatted on his left bicep - was last linked to The Walking Dead's Lauren Cohan, while she ended her engagement to her Yoü and I video stud Taylor Kinney in 2016.

Aside from her alleged nuptials, the Five Foot Two stunner has her Las Vegas residency at MGM Resort's 5200-seat Park Theater starting next December to look forward to planning. 

According to the Las Vegas Review-Journal, the Cure crooner signed a two-year contract agreeing to about $14.4M for 36 shows, averaging $400K per concert. 

But first, Lady Gaga will kick off the third leg of her 59-date Joanne World Tour on January 14 at the Palau Sant Jordi in Barcelona.

It's unclear if Mother Monster's grueling schedule will allow her to return to her Manhattan hometown January 28 to compete for two trophies at the CBS-broadcast Grammy Awards.

The Oscar-nominated songwriter's record Joanne scored a nomination for pop vocal album and her single Million Reasons is up for pop solo performance.

2018 will also see Gaga make her big-screen debut as Ally in Bradley Cooper's remake of A Star is Born, which hits US theaters May 18.