The "Cry Me a River" hitmaker has boasted that the acclaimed LP, which included the hit singles "SexyBack", "My Love", and "What Goes Around...Comes Around", "still hits" more than a decade later.
Justin, 40, wrote on Instagram alongside a series of clips and photos from the album's era, "15 years ago today, I released my 2nd album…FutureSex/LoveSounds. This album changed my life. Every album is a different chapter and special to me but, this one??? I don't even know if I have the words."
"I'm often asked what my favorite song on the album is but they're all my babies so I can't pick. But I do know this: album STILL HITS."
The anniversary comes after Timbaland teased a "FutureSex/LoveSounds" sequel.
The 49-year-old DJ and record producer worked with Justin on the acclaimed album and hinted last year that there may be a "part two" in the works.
Timbaland posted a throwback picture of himself and Justin performing together on Instagram, and wrote, "FUTURE SEXY LOVESOUNDS pt (two)," alongside two emojis with zipped lips.
No other information was shared by the "Apologize" hitmaker, leaving fans in a frenzy as they tried to decipher what the post could mean.
Earlier in 2020, Justin revealed he had been working on some new music with the likes of Kaytranada and Hit-Boy, and said at the time he "definitely" wants his long-term collaborator Timbaland involved.
Timbaland has worked with Justin several times after first producing his 2002 hit single "Cry Me a River", and has also worked as a producer on his "The 20/20 Experience" album in 2013, and on several tracks for his 2018 record "Man of the Woods".