The Merseyside outfit are said to have agreed a fee of £25million, which includes various performance related bonuses and add-ons.
Reds boss Jurgen Klopp is hoping to have the transfer wrapped up in the next few days, with the Premier League club currently preparing for the first game of their pre-season tour of the United States.
Wijnaldum has four years remaining on his current deal and could link up with the Liverpool squad at their Stanford University training base on Thursday to undergo a medical.
The Netherlands international was ever-present for the Magpies in the Premier League last season, making 39 appearances and scoring 11 goals.