The Scotland international becomes the Reds's third major signing of the summer following the arrivals of Dominic Solanke and Mohamed Salah
Liverpool have completed the £8 million signing of Hull City full-back Andrew Robertson.
The Scotland international has signed an X-year deal at Anfield having completed a medical on Thursday, with his fee set to rise to as much as £10m should he meet certain criteria during his time on Merseyside.
Robertson's arrival could allow James Milner to move back to a more familiar role in midfield after he filled in admirably at left-back for much of last season while Alberto Moreno and Jon Flanagan remain in Jurgen Klopp's squad.