The Merseyside club today announced the 24-year-old England midfielder has signed a long-term deal, understood to be five years, at Anfield.
Liverpool moved for Oxlade-Chamberlain this week after the player turned down the chance to join Chelsea.
Neville worked with the Ox during his coaching role at England.
He tweeted today: “He has lots of potential and talent. Needs to improve his Fitness record , concentration in games and assists / goals.”
Oxlade-Chamberlain played for Arsenal against Liverpool in the 4-0 defeat at the weekend.
He wrote: “He was one of Liverpool’s best players last Sunday.
“I’ve never seen him like that. It wasn’t good.”
Oxlade-Chamberlain is currently on international duty. He underwent a medical at England’s St George’s Park training base after agreeing terms with the Reds yesterday.
Speaking from the England camp, where he is preparing for World Cup qualifiers against Malta and Slovakia, Oxlade-Chamberlain said: “Firstly, I’m delighted to have signed for Liverpool and a big thank you to everyone here at the FA that has made this possible, using the facilities. It has been a massive help.
“I’m not going to say too much today. I’m here with England and we’ve got two big games coming up, so I want to focus on them.”
The signing is Liverpool’s second of the week after a deal to bring in midfielder Naby Keita from Red Bull Leipzig next summer was completed on Tuesday.
