Caswell won a contract for her own HGTV show on Monday night's season finale.
The competition was judged by noted designers Vern Yip, Genevieve Gorder and Candice Olson, while Season 1 winner David Bromstad served as mentor.
"Being chosen as the next 'HGTV Design Star' is the most amazing thing that has ever happened to me. I have won my life's dream," Caswell said in a statement.
Her five-episode series, "HGTV Great Rooms," is to premiere Saturday.
"Meg embodies so many unique qualities," said Yip. "The moment you meet her she instantly puts you at ease, explains design in an entertaining way and has an evident design talent that blossomed into something stunningly beautiful over the course of the season. I'm really looking forward to seeing her new series."