Anderson is in Scot Gemmill's squad for European qualifiers against Kazakhstan and Belgium next month.
The 18-year-old Whitley Bay-born player featured in a training-ground friendly for England Under-19s in March after previously representing Scotland at under-16, under-17 and under-18 level.
Anderson made two substitute appearances for the Newcastle first team in January and has recently returned from a hip injury.
Gemmill has also called up Leeds winger Stuart McKinstry and forward Aaron Pressley, who is on loan at AFC Wimbledon from Brentford.
The head coach said: "It is really important to give an opportunity to as many players as we can, but obviously we have to pick the right ones and any time we bring new ones in, it means others have to drop out.
"But over the period I am very conscious and the staff are very conscious to give the opportunity to as many players as we can that we think deserve it."
Pressley - the son of former Scotland defender and coach Steven Pressley - has scored four goals this season for AFC Wimbledon. He was previously with Hearts and Aston Villa youth academies.
McKinstry made his Leeds debut in a Carabao Cup win over Fulham last month, netting a penalty in the shoot-out. The 19-year-old moved to Leeds from Motherwell in the summer of 2019.
"He is doing great," Gemmill said. "He is obviously at a great club, playing for a really top coach that is highly regarded around the world. It's fantastic he has put himself in this position but it's also just the start of his professional career."
Gemmill has again called up Bologna left-back Aaron Hickey, who dropped out of this month's defeat by Denmark through injury. The 19-year-old's last Scotland caps were for the under-17s in early 2019.
Aberdeen right-back Calvin Ramsay is absent through injury, while Norwich goalkeeper Archie Mair earns a recall despite not yet featuring during a loan spell with Lincoln.
Scotland Under-21s host Kazakhstan on November 12 and Belgium four days later, both at Tannadice.