Todd Chrisley -- I'm Doing Country Music, Y'all!

Todd Chrisley of USA's "Chrisley Knows Best" is ready to become a Nashville heavyweight as a singer/songwriter ... TMZ has learned.

Jody Williams and Leslie Roberts, the head honchos of music publisher BMI, inked the deal with Todd, and it's a sweet one.

Right out of the box, he'll be doing a collabo with songwriter Shane Stevens -- who's written songs for Selena Gomez, Carrie Underwood and Lady Antebellum -- and they'll be joined by award-winning country star Sara Evans.

We’re told the power trio is planning to meet in Nashville this week to get started on their first song.

Talk about being set up for success. Don't screw it up, Todd.