The TODAY co-anchor announced the joyous news on the show Monday that they will be tying the knot after six years together.
"I have to tell you something that a friend of mine, a friend of ours, asked me to let you guys in on a secret,'' Hoda said. "I'll give you her initials. Her initials are Hoda Kotb, and she's engaged."
Hoda had hidden her engagement ring and secretly slipped it on before making the announcement on-air.
"My heart has literally been pounding,'' she said.
Joel proposed during dinner over the weekend while the two were on a tropical vacation.
"We ended up having a little dinner on the beach," she added. "And he was like, 'I have something else I would like to say,' and he said some beautiful things, and then he got down on one knee. Then he said, 'Would you be my wife?'''
Hoda had no idea that a proposal was coming.
"I was totally shocked,'' she said. "He had a good poker face."
Hoda gave more details about the sweet moment on TODAY with Hoda & Jenna.
"He was crying, I was crying, and I looked at him, and I thought to myself, 'Oh my God, this is that thing,''' she said. "And the other weird thing is like, I felt different from that moment on, which is weird because we have two kids, we've been together for six years, so why would I feel different? I don't know.
"I feel like it's grounding."
He told her that he had the ring in his pocket for a while and had nearly popped the question when the two went bowling together recently.
"The ease with which he kind of kept the secret, but was excited inside, is the way he lives his life,'' Hoda said. "So I always feel like I'm with (a) rock steady (person), and that matters."
Joel, 61, has been with Hoda, 55, every step of the way during a jubilant period in her life in which the couple have adopted two children together, daughters Haley Joy, 2, and Hope Catherine, the latter of whom joined their growing family in April.
"How am I going to explain (to the girls) your parents are going to get married?" Hoda joked. "We're still trying to figure out that part."
She also reflected on when she first told Joel that she wanted to adopt a baby girl. He thought she was going to break up with him because she was so serious.
"He said, 'So when you asked about adoption, it was the easiest yes in the world,''' she said.
Hoda and Joel first met when she was signing some autographs at an event with "Wall Street guys" who were "bored," she told Andy Cohen in 2015 on "Watch What Happens Live."
One of the men in line for an autograph turned out to be Joel.
"I said, 'Who should I write it to?'" she said. "And he said, 'How about to me?' And I said, 'How 'bout to you?'"
The two ended up on their first date together with a little help from Joanne LaMarca Mathisen, the executive producer of TODAY with Hoda & Jenna. Hoda thanked Mathisen on TODAY Monday for setting up that fortuitous meeting.
"My husband actually made Hoda go to (the event where she met Joel), I did not, for the books,'' Mathisen joked on TODAY in June. "She saw Joel and thought he was really sweet and fun, and he was a friend of a friend of mine, and Joel happened to think Hoda was sweet and fun."
Hoda got emotional in September when she reminisced on TODAY about the first time Joel told her he loved her.
"He was the first person to say 'I love you,' and I remember him saying it to me," Hoda said. "And after he said it, I remember just sitting there because I wanted to feel it for a minute.
"Like, just to sit with that for a minute — somebody saying, you know, he just said, 'I love you,'" she continued. "And I paused, and he goes, 'Don’t leave me hanging out here in the abyss.'''
Their love has only grown over the years as they became parents to their two little girls. Hoda was asked last year by Cohen on "Watch What Happens Live" if she eventually planned to marry Joel.
"I’m going to be with Joel until my last breath,'' she said.
Congrats to the happy couple!