Butler announced the deal publicly via his Twitter account, first saying he had "some BIG news for" his followers early Friday before divulging it in his own unique way: "Like a good neighbor State Farm is there.....!!!!! w/ a new job! Everybody I'm a #Spur :) #winning"
He was selected by the Miami Heat with the 42nd pick in last June's NBA Draft despite his ACL injury and signed a contract that included guaranteed money at the end of August. But by the end of October, Butler was waived by the Heat.
With the Spurs, the Newark, N.J., native will again wear the No. 1 jersey he donned during his time at West Virginia.
Butler finished his college career with 107 career wins, the most in Mountaineer program history. As a senior he was named first team All-Big East, averaging a team-high 17.2 points, 6.2 rebounds and 3.1 assists in 38 games.
He scored 2,095 points during his WVU career, ranking third in school history behind Jerry West and Hot Rod Hundley.
Butler also ranks among school leaders in career double-figure scoring games (1st, 108), field goals (3rd, 741), three-pointers (4th, 205), free throws (5th, 408), rebounds (11th, 800) and steals (12th, 154).