According to a record of marriage obtained by ABC News, the Olympic gold medalist wed former Miss California USA Nicole Johnson in Paradise Valley, Ariz. on June 13.
A rep for Phelps has not yet responded to a request for comment.
Phelps and Johnson, both 31, announced their engagement in February 2015. They welcomed their son, Boomer, this past May, and a few months later, Johnson brought the baby to Rio to cheer on Phelps at Olympics. Having his family on-hand was an emotional experience, Phelps said.
“When I got out of the warm-up pool for the last time to get ready to go up to the blocks, I have the white shoes that I wore pretty much every finals,” he told ABC News. “In the left foot, there's a footprint of him, inside of my shoe, and I put my shoe on and I looked down at it and I started to get emotional because I knew he was in the stands."
“Being able to have our first child witness my last Olympics ever, my last ever, I mean, it's just dream come true after dream come true,” he added.