By TMZ Sports

WBC middleweight champion Saul "Canelo" Alvarez is off the hook in his $9 million lawsuit with former IBF junior flyweight champion Ulises "Archie" Solis -- as both sides have reached a settlement ... TMZ Sports has learned

According to court docs, the settlement was reached on Thursday. Terms of the deal have not been disclosed.

Solis had claimed Alvarez hit him so hard it broke his jaw ... forcing him to cancel future fights, so the IBF stripped him of his belt. Solis also lost a few teeth and had to undergo two surgical procedures on the jaw. Solis had tried to bring criminal charges against Canelo in Mexico, but he was unsuccessful in doing so.