The University of Texas graduate will write for the publication's "Paper Napkin Interview," as well as a blog called "The Daily South," NBC's "Today" reported.
Bush Hager is also a contributing correspondent for the New York-based "Today" morning news program.
"I am kind of a homesick Southern person, a Texan living here in New York," she said on Wednesday's edition of "Today." "I love New York. I love the energy of it. I love the fast-paced nature of New York, but I do miss the slow Texas way."
Southern Living editor-in-chief Lindsay Bierman said he was "instantly charmed by Jenna's style and charisma."
"[Jenna's] Texas roots, passion for the South and proven reporting chops make her a natural fit for the brand," Bierman told "Today."