UPDATED 03:11 2nd September 2016
Toffolo enjoyed loan spells at Swindon Town, Rotherham and Peterborough prior to his arrival at Glanford Park.
While at Swindon he was part of the side that reached the final of the League One play-offs during 2014-15, scoring one goal in 30 appearances.
He played seven times while on loan at Championship side Rotherham last season, and also made the same number of appearances while on loan at League One side Peterborough later last term.
He has also played for England at U18, U19 and U20 level and will wear the No 15 shirt while with the Iron.