Robertson spent three seasons with the Tigers following his arrival from Dundee United, and joins the Reds on a long-term contract.
The fee is undisclosed but is thought to be worth around £8million to the Sky Bet Championship club.
How could Liverpool line up next season?
Burnley made the early running for Robertson after Hull’s relegation from the Premier League but no deal was forthcoming, opening the door for Klopp;
The 23-year-old told the Liverpool club website: “It feels a wee bit surreal just now. Obviously I’m delighted. There’s been a lot of speculation over the last couple of weeks but I’m glad that the deal’s finally been done and I’m a Liverpool player.
“My family are proud of what I’ve achieved so far and they’re all over the moon with the move, as well as me of course. We’re all just looking forward to being part of the Liverpool family now.
“There’s not many, if any, more special clubs than Liverpool. When you grow up as a kid you dream of playing with big clubs such as Liverpool and to make that a reality is a dream come true for me.
“I just want to prove to people that I can do it at this level, and hopefully I manage to do that this season and go on to do good things for this club.”
Robertson joins Salah and Solanke as summer additions to Klopp’s squad (Getty)
Announcing his departure, Hull said: “The 23-year-old full-back left the Tigers’ Portuguese training camp earlier this week to undergo a medical and finalise terms with the Merseyside club.
“Robertson arrived at the KCOM Stadium from Dundee United in July 2014 and went on to make 116 appearances for the club in all competitions, scoring five goals.
“Everybody at the club would like to thank Andy for his efforts in a black and amber shirt, and wish him well for the future.”
Robertson spent three seasons with Hull following his arrival from Dundee United (Getty)
Midfielder Kevin Stewart has moved in the opposite direction on a three-year deal.
The former Tottenham player made 20 appearances for Liverpool, including 11 in the Premier League, and has played for Crewe, Cheltenham, Burton and Swindon on loan.
Having flown to Portugal for his medical, Stewart could make his first Hull appearance in Saturday’s friendly against Benfica.
Stewart told the Hull website: “I’m delighted to sign for the club, I can’t wait to get started and get my boots on.
“It’s an exciting move for me and I’m looking…