The country music star recalled the ups and downs of his marriage to Hill, also a singer, and looked to the future in an Instagram post Tuesday.
"24 yrs....... These years have rushed by in a series of beautiful, painful and unexpected moments...." McGraw wrote. "We have loved, laughed and cried through exciting, inspiring and heartbreaking events in our lives together."
McGraw and Hill married in 1996 and have three daughters, Gracie, 23, Maggie, 22, and Audrey, 18. McGraw praised Hill as a role model for their children.
"U have been a role model for 3 remarkable young women who have made me a better man than I ever thought I could be....." McGraw wrote.
'The future will surely hold more of all these things. It only matters if I'm with you. If only works if I'm with you. My oxygen only exists if you're by my side," he said. "Forever and always living and loving our way through anything @faithhill."
In September, McGraw posted a photo of himself and Hill sharing a kiss on her birthday.
McGraw called Hill the love of his life while celebrating the occasion in 2018.
"From the first time we met, I knew that she was the love of my life forever. No matter the ups and downs, the happy and sad or the good and bad," the singer tweeted.
"She's so special and so loved by us. Happy birthday my love," he said. "When I wake up next to you in our 80's. I'll smile at the life we've built."
McGraw and Hill released their first joint album, The Rest of Our Life, in 2017. McGraw released his 15th solo album, Here on Earth, in August, and described the album as a "tapestry of life" on Today.