The young Magpies booked their spot in the last four following a 4-1 win against Bedlington Terriers at Whitley Park as goals from Amadou Diallo, Ellis Stanton, James Huntley and Kyle Crossley sealed a comeback victory against the Northern League Division Two outfit.
Their reward is an away tie against Ashington, who advanced into the semi-finals after claiming a 1-0 away win against West Allotment Celtic.
Newcastle’s youngsters, bidding to lift the trophy for the first time since 2018, reached the final of the competition in 2022 before suffering a narrow 3-2 defeat against Blyth Spartans at St. James' Park.
Northumberland Senior Cup semi-final draw:
Ashington vs Newcastle United Under-21s
Blyth Town vs Newcastle Benfield