Tyrell, the drummer of country music trio Love and Theft, first met the "Run to You" singer when they each served as opening acts on Tim McGraw's Southern Voice Tour in 2010.
Over the Fourth of July weekend, Tyrell, 24, popped the question to Scott, 25, while the two were enjoying a day at the lake in Tennessee.
In April 2010, Scott told Us she felt "blessed" that Lady Antebellum formed the way it did. "Whatever just happens naturally is what we go with," she said. "But when it all comes down to do it, there's a lot of timing and fate involved."