John Calipari is officially the head coach of the Arkansas Razorbacks -- the school just announced the hire on Wednesday ... with the Hall of Famer slated to make at least $7 million a year.
Arkansas was excited to share the big news ... posting a hype video to welcome the former Kentucky Wildcats leader to the program.
Cal inked a five-year deal for the new gig ... which includes the base salary and $1 million signing bonus ... as well as more dough for postseason success and each season he sticks around.