Morton spent the 2022/23 campaign on loan at Blackburn, but after 46 appearances for Rovers a broken foot curtailed his progress in April.
The 20-year-old returned to full training with Liverpool towards the end of August, and deadline day brought another temporary move.
This time, Morton has joined Hull on a season-long deal, with no purchase option involved in the transfer.
Having signed a new long-term contract at Anfield in January, Morton remains in Jurgen Klopps first-team plans, though this summers rebuild has outlined the difficulty in breaking through.
Currently behind Alexis Mac Allister, Dominik Szoboszlai, Thiago, Wataru Endo, Curtis Jones, Harvey Elliott, Stefan Bajcetic and new signing Ryan Gravenberch in the pecking order, Mortons minutes would be limited.
Joining the Tigers, who sit eighth in the Championship ahead of the weekends fixtures, will give the midfielder a chance of regular starts.
Hull are managed by their former defender Liam Rosenior, with nine other signings made this summer including ex-Everton loanee Ruben Vinagre.
Morton can play in both deep and advanced midfield roles, though the majority of his appearances for Blackburn came as a No. 6.
He made nine appearances for Liverpools first team in 2021/22, including starts against Porto and AC Milan in the Champions League and Tottenham in the Premier League.
The hope is that he can continued his progress with Hull before returning to take part in next summers pre-season under Klopp.
All the best, Tyler.