The 29-year-old Holdsworth has signed a one-year deal with the Sharks, with his addition providing much needed back-up to incumbent halves pairing of Todd Carney and Jeff Robson.
A member of the Hull team which won through to the English Challenge Cup Final, Holdsworth was named Man-of-the-match in his teams semi final victory over Warrington.
Holdsworth, who began training with the Sharks this week, started his NRL career at the Dragons in 2004, before a switch to the Bulldogs saw him play four seasons and 66 NRL games at the Canterbury club from 2006-2009.
From there Holdsworth joined the Salford Red Devils in 2010, before spending the 2013 season at Hull.
Following just his second day of training with the Sharks Holdsworth taped a brief interview with Sharks media, with the video now playing on Sharks TV