The 6ft forward is the first of Peter Taylor's closed season signings. He joins for an undisclosed fee, thought to be a six figure sum.
24-year-old Allsopp is a former Australia Under-21 international. He was brought to the English game in 1998, signing for Manchester City. He scored 6 goals for the Blues in 2 years, with most of his appearances as substitute.
He went on loan to Notts County in 1999, scoring in one of his 3 games. He then had a spell at Wrexham, scoring 4 in 3, while he failed to score in a loan deal with Bristol Rovers.
But he was scoring again when he went back to Meadow Lane in November 2000, finding the net 4 times in 3 games. That persuaded them to pay Man City £300,000 to keep him permanently. Since joining them he's started over 1000 times and scored 50 goals, 12 of those coming this season.
Allsopp says he "can't wait" to get his Tigers career underway after signing a 3-year contract today.