The 25-year-old joins the Sharks on a two-year-deal after a short stint with Brisbane and Queensland Cup side Easts, with whom he was dually-registered.
His arrival at the Sharks will be a welcome boost for the club, who have suffered defeats in the opening two rounds of the NRL.
“Tim has a lot of potential and it will be great to see him realise it here with the Sharks.
“We would like to thank Easts Brisbane and the Broncos for their support to provide such a positive outcome for Tim.”
Smith joins the Sharks with a glowing endorsement from captain Trent Barrett who played with him whilst at Wigan.