The couple both shared a portrait of the nuptials, which took place Nov. 4 at Rosewood Castiglion del Bosco in Tuscany.
Upton wore a gown by Valentino.
"I feel so lucky that I got to marry my best friend!! @justinverlander," she captioned the shot. "Thank you to our family and friends for making this weekend so fun and magical!"
Added Verlander: "Happy wife happy life! What an amazing beginning to our journey together! @kateupton #justmarried"
Upton, 25, and Verlander, 34, first met in 2012 and became engaged in 2016. During the World Series and games leading up to it, the model was a mainstay at Astros games, though she did make a pit stop in New York City late last month for her bachelorette party.
"Cheers to getting pampered @GuerlainSpaNY and being showered with [love]," she captioned a photo.