Ryan Lochte I'm Engaged ... She Said Jeah!!!

Olympic legend Ryan Lochte is diving headfirst into a new chapter ... because he's engaged to Molly Gillihan!

TMZ has learned Ryan popped the question last week at a restaurant called Prime and Pearl in Gainesville, FL -- where the two had their first date -- while celebrating their move to Missouri.

Ryan and Molly walked a path of red rose petals and sat in the same booth they did on their first date. A card was waiting, which asked the Molly the all-important question ... she turned, saw Ryan down on one knee, and gave an overjoyed "yes!"

Check out pics of the immediate aftermath ... the two locked lips in the middle of the restaurant, and Molly flashed the massive ring , which ya gotta see for yourself.

The happy news comes after Ryan posted a lengthy birthday tribute to Molly on Instagram ... pouring his heart out about how she helped him through one of the toughest stretches of his life.

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Ryan and Molly went Instagram official over Fourth of July weekend last year, though they've been dating for about 14 months. They discussed rings about 6 months into the relationship ... with Ryan wondering if she preferred gold or silver ... and Molly insisting she just wanted something simple.

We asked Ryan about the engagement ... and he told us, "I'm on cloud 9 she said yes. I'm happy this is my new beginning, and I couldn't do it without her."

This will be Ryan's second marriage ... he married Kayla Rae Reid back in 2018, but she filed for divorce in June 2025 and listed their date of separation as March 2025.

It's been a busy year for Ryan ... he's recently taken a coaching job with the men's swim team at Missouri State University ... and now, he's got a wedding to plan, too!