The couple were rumoured to have tied the knot earlier this month with reports suggesting they married in a "low-key" ceremony, but are planning to hold a "bigger" celebration at some point later in the year and now the groom's proud dad has opened up about the big day.
During an appearance on 'The One Show', Jon said of the couple: "They're great. They're absolutely fantastic. It was a very small family wedding, and the bride looked gorgeous, and Jake is happy as can be. It's true".
A source previously told The Sun newspaper: "Millie and Jake quietly said their vows in America last weekend.
"They are planning a bigger ceremony in the US later this year but now they have legally married and done all the paperwork".
"It was a very low-key, romantic affair with their closest family with them as they said their vows".
Millie, 20, and Jake, 22, were enjoying a family vacation in the Maldives last spring when the rocker's son proposed during a scuba diving session.
Speaking on the 'Table Manners' podcast, she told hosts Jessie and Lennie Ware: "Basically, I was on holiday with my parents and Jake. I had a feeling; I packed a white dress just in case, let's just say that, and I had my [nails] done in the way I wanted.
"I don't like surprises, I usually know when one is coming. There were conversations before we left about proposals and what I would like, what I wouldn't".
"I thought it would be a very good place to choose. We were in the Maldives, so Jake and I were diving one morning, his parents were there".
"He just asked if I could be up at 8am to be up for a dive. And the night before, I said 'Could we cancel that?' and he said no, and he never really says that".
"A few months before, he said he would never propose while diving. There was a video we saw online and he said 'I'd never do that because if you got too excited, you wouldn't be able to breathe', so I was like 'Well, that's a good point'".
"And I thought he wasn't going to do it and then when I went under - it was actually an hour of diving - before he did it".
But the 'Stranger Things' star was so excited and dropped the ring in the heat of the moment, which prompted her husband-to-be to do a heroic "swoop" to the seabed and grab it as she floundered and panicked that it had disappeared forever.
She added: "I was taking really deep breaths because I was so excited and then we floated to the top. He dropped the ring, well, I dropped the ring because I went to show him and it slowly slid off. I probably could've stopped it and then nothing was slow about this plummet. It plummeted so fast, so quickly. I really, truly, thought it was gone".
"I watched it fall to the bottom of the ocean. He saw it happen, which I'm so proud of him [for], he just threw himself so deep underwater and did this cinematic swoop and when he opened his hand, it was in there."