The Black Cats player of the year is set to be on Merseyside next week to discuss personal terms and to undertake a medical.
The 24-year-old arrived in Wearside in June 2010 for 2million from Belgium side Sint-Truiden and has gone on to make 101 appearances for Sunderland.
Mignolet impressed greatly last season keeping 11 clean sheets and played every single league game in a disappointing season for Sunderland.
The Belgium international believes a move to a bigger club will greatly improve his chances of being Belgium’s number one before the 2014 World Cup in Brazil.
It is said that Mignolet wants assurances over his place in the team as Reina has said he will stick to his contract unless a big club come in for him, with Arsenal and Barcelona both being heavily linked with the Spanish goalkeeper.
Mignolet will possible be The Reds fourth signing by the time he arrives, as The Reds have agreed deals for Kolo Toure and Iago Aspas while Seville winger Luis Alberto is in Liverpool to agree personal terms and complete a medical.
Liverpool are also targeting Sporting Lisbon defender Tiago Llori and Shakhtar Donetsk midfielder Henrikh Mkhitaryan.