The Reds saw their £25 million bid for the Magpies star accepted in the early hours of Thursday morning, before the 25-year-old passed a medical on Friday ahead of his move.
Wijnaldum joins on a long-term contract, and will travel immediately to link up with Jurgen Klopp‘s squad for Liverpool’s pre-season tour of the US.
Reports suggest the fee is an initial £23 million with a potential £2 million more in add-ons, and the player will be on £75,000 per week.
Wijnaldum will wear shirt number 5, not 8 as had been rumoured.
A powerful, intelligent midfielder capable of operating in a number of roles, the Netherlands international will add to Klopp’s options across the middle of the park.
Wijnaldum could make his debut for the club against Chelsea in the International Champions Cup on July 27, with further friendlies to come against AC Milan, AS Roma, Barcelona and Mainz 05.
Likely a replacement for the departing Joe Allen, Wijnaldum will provide a significant boost to Klopp’s squad. He could make his first appearance in a Reds’ shirt against Chelsea in Los Angeles on Wednesday (Thursday morning UK).