Liverpool have agreed a £8 million move with Hull City for the left-back.
The Scotland international will compete for a first team spot at Liverpool with James Milner and Alberto Moreno, and adds valuable depth in a position of need.
Andrew Robertson celebrates scoring for Hull
Roberton is not the marquee name Liverpool fans might have had in mind for the position, but he does strengthen the squad and it is important manager Jurgen Klopp is addressing the left-back spot.
The fact the club are spending a small amount on a left-back offers hope that funds are being saved for a big move to bring in a player in another position, with centre-back target Virgil van Dijk and midfielder Naby Keita both options - despite their respective club's determination not to sell.
Scotland's Andrew Robertson in action
Robertson has left Hull's training camp in order to undergo his medical, and the Reds could announce a move later this week.
The 23-year-old made 33 Premier League appearances for Hull City last season, scoring once and providing two assists.