The couple credits the unforgettable moment to the generosity of the two performers - and the power of social media - after the bride's brother, Mike, sent a direct message asking them to attend.
"People say that the wedding is going to be the best day of your life, but, I mean, that was just above and beyond anything I ever could have expected," said bride Tessa Kindelin.
Kindelin and her husband, Brendan Harty, were celebrating their wedding at the Adler Planetarium when the unexpected unfolded. Although Sheeran and Garrix were in Chicago that weekend, the couple initially never imagined the artists would be part of their guest list.
"We had kind of joked about and talked about, you know, 'What if we invited them to our wedding?'" Kindelin said.
That joke turned into reality when her brother reached out directly to Garrix on social media. The musicians later shared the exchange online.
"He's got a DM from someone saying, 'Can you crash my sister's wedding?' So, were going there," Sheeran said in a post shared on social media.
Soon after, the singer-songwriter and DJ made their entrance into the Adler Planetarium, stunning guests and the couple alike.
"The crowd erupted," Kindelin said, describing the moment. "I knew that Mike had been talking to Martin Garrix, but I had no idea that Ed Sheeran was coming with them, too. So, I came up from the crowd and I, you know, heard their song playing. And then I saw Ed, and I was like, 'Oh my God!'"
"I can't believe they both came. It was unbelievable," she added.
Harty described the moment as equally surreal.
"It was surreal. Yeah, it was disbelief," he said.
Kindelin said the surprise still feels unreal even after reviewing videos captured by friends.
"It was amazing. I have watched that video multiple different angles from all my friends and I still can't believe that that happened," she said.
The couple's wedding videographer, Lawrence Trantham, witnessed the moment firsthand.
"You could almost like - the bride was about to pass out, that's how shocked she was seeing Ed Sheeran," Trantham said.
"Everyone was almost basically bouncing off the walls, jumping up and down, like some people was like completely shell shocked, mouth agape, eyes wide open," he added.
For Harty, the experience also resonated with family members who are longtime fans of Sheeran.
"My sisters are huge Ed Sheeran fans. They have been going to concerts for over a decade," he said. "So, they got the best of both worlds. All the families were just so elated."
The performance added another layer to what the couple already described as a perfect celebration.
"I mean, I got to dance with my wife and Ed Sheeran sang perfect to us. So how could it get any better?" Harty said.
The couple is now preparing to leave for their honeymoon in Hawaii. Kindelin said her brother's role in making the moment happen has secured him lifelong gratitude. She joked that he is now exempt from giving her gifts for the rest of her life.