The Stadler-built class 555 has carried out a test runs, where it was seen stopping at Metro stations including Four Lane Ends.
Metro operator Nexus said it was "proud to see" that the first test run had gone without a "glitch".
A £362m fleet of 46 trains will gradually enter service later this year, replacing rolling stock that is more than 40 years old.
Extensive testing and driver training is to be carried out across the Metro network.
Nexus's major projects director Cathy Massarella said it will take several months before the new trains can enter service.
"We’re really pleased to say that our new Metro train has completed its first test run out on the network and performed really well," she said.
"This a considerable period of detailed testing to get the trains ready for our customers".
The first test was a return journey between South Gosforth and Monkseaton in the early hours of the morning.
The fleet will be based at the depot in Gosforth.
Ms Massarella said: “It was a proud moment for us to see the train leave the depot at Gosforth and join the mainline.
“Once the trains are in service they are going to be transformative for our customers and our workforce in terms of comfort, quality and reliability."
The trains are being constructed in Switzerland, but some have been sent to the Czech Republic to allow drivers to familiarise themselves with them.
Claudius Oblasser, project manager for Stadler, said the first run marked the start of a "rigorous programme" of testing.
"Scores of tests will be carried out over the coming month to make sure it’s ready for passengers.
"They will cover every aspect of the train’s design, from the power supply and braking systems to digital passenger information boards and CCTV cameras."
Nexus said the new trains had been designed to cope with the toughest weather conditions, cut energy consumption and make accessibility easier.