Liverpool have been keeping a close eye on Ilori since having a £3m bid for the defender turned down in June.
Manager Brendan Rodgers was initially thought to be put off by Sporting's £6m asking price, but reports that the 20-year-old recently turned down a contract offer at the Portuguese club led to Liverpool rekindling their interest earlier this week.
The two clubs are thought to have agreed a fee in the region of £8m, with Ilori set to travel to Anfield to discuss personal terms and undergo a medical.
The Portugal Under-20 international was also reportedly on the radar of Monaco and Valencia, but he is now expected to complete his move to Liverpool in the coming days.
Ilori would potentially be available to play for England having been born in London and only played for Portugal at youth level.