Megan Thee Stallion Sizzles in Bikini for 'Baywatch'

It's looking like a "Baywatch" girl summer for Megan Thee Stallion ... 'cause she was just spotted showing off her body-ody in a bikini on set!!!

Check out the footage ... the rapper hit the sand in Long Beach in an orange and white bikini paired with a matching sarong ... and it looked like she was feeling herself as she flaunted her rock-solid abs while cameras were rolling.

Her cameo here may involve a musical number too ... 'cause eagle-eyed fans spotted a Megan Thee Stallion stage on set.

Of course, Megan's not the only one who's been spotted filming for the highly anticipated reboot. Livvy Dunne was seen getting wet 'n wild for a car wash scene with Noah Beck.

Livvy's also been seen alongside Brooks Nader in their matching iconic one-piece red swimsuits. We're told there's been some "tension" between them over who's going to be the series' Pamela Anderson ... but for now, we're just concerned about all the sizzling swimsuit shots coming out of the reboot.