The songstress shared a sweet message and a slideshow of snapshots from different times throughout their relationship.
"15 years. Proud of us babe," she wrote. "See, sometimes being stubborn pays off."
"What a wild ride it’s been, once we learned how to stay in our race line," she wrote. "Here’s to at least the next 15 months hahahah. I love you and I love our family. "
Hart, meanwhile, shared a tribute of his own. The 45-year-old off-road truck racer and former motocross star posted a beaming home video of Pink, hanging out on the deck of a boat while dancing and drinking from a red plastic cup.
"15 years w/ this amazing woman! Damn, baby!!!!!" Hart wrote. "There is no other woman that I would want to go through this crazy world with than you."
"Thanks for being a great friend, wife, mother, and person," he added. "Throw your 🖕🏻 in the air."
The joyful posts come after a challenging year for the couple's family. Amid the coronavirus pandemic, Pink and their son Jameson contracted COVID-19, which proved to be a truly harrowing battle that they eventually managed to overcome.
See the video below to see more on the enduring couple.