The 45m-long vehicle successfully completed a test run from Haymarket along Princes Street to York Place in the early hours of the morning.
It travelled at walking pace while it was checked by engineers and contractors.
Edinburgh City Council transport convener Lesley Hinds said: “Getting a tram on to Princes Street is the culmination of an intensive period of hard work to get this project back on track. It is an important step forward but all eyes are now on the launch of passenger services in May.
“With the first successful test in the city centre, we’re ready for more frequent testing along the length of the route in the new year.
“It’s important to recognise the significance of this test phase. There is much to be done and we’re at a vital stage in the project, ensuring that all the appropriate tests and checks are done.”
Transport minister Keith Brown said: “The successful test runs on Princes Street and at Haymarket over the past few days are welcome landmarks for the tram project.
“Seeing the trams operating in the city centre is a sign of real progress for the project, following the delays and frustration of the past.”
The frequency and speed of tram testing will increase over the coming weeks, although few runs are likely before new year, the council said.
After six years of construction, the trams are due to begin transporting passengers by May.
The project has been hit by problems including a long-running dispute between the council and its contractor.
Work restarted last year on a more expensive but much shorter line. It was originally intended that trams would run from Edinburgh Airport to Newhaven in the north for £545 million, but the route will now terminate in York Place in the city centre and cost £776 million. Dozens of well-wishers watched the night-time test run, which saw the tram leave Haymarket Yards at 11pm and travel along the final section of the line. Its journey is a vital part of getting the capital’s £776 million tram project ready for its launch in May.
Members of the public, undeterred by the wind and rain, took photographs of the 45-metre long white tram as it moved at walking pace accompanied by dozens of engineers monitoring its every move. The journey, with frequent stops for checks, was due to end at York Place at 4am today.
The first stop was at Haymarket where engineers used spirit levels to check the distance from each carriage exit to the edge of the platforms.
‘Enthusiastic’ onlookers turn out to see tram
Among the onlookers was Iona MacKinlay, 69, a retired teacher from Currie, who said she intended to follow the tram to the end of its test run.
She said: “It’s an exciting night to see it for the first time on the streets of Edinburgh. I went to school, Liberton primary, on the tram from Dalkeith Road.”
Ms MacKinlay said the controversy surrounding the trams had not curbed her enthusiasm.
“I think these big projects always run over time and budget but Edinburgh really needs trams because very soon all the pollution will just get too much.”
Chris Malcolm, 70, from Goldenacre, Edinburgh, said: “This is an important milestone.”
Lesley Hinds, the council’s transport convener, said: “We recognise it’s been a long road getting here . . . but at long last, it’s good to know there’s a tram approaching Princes Street.”
The last tram to trundle along Princes Street was on 16 November 1956.