The landmark occasion is the second this year for the Cheshire arm of the Luton-based vehicle manufacturer, after it celebrated its 50th anniversary of car production in June.
Officials and dignitaries gathered at the former site of RAF Hooton to see the Astra be signed-off.
“My congratulations to the company and its dedicated workforce for making this possible.”
Vauxhall started building its compact cars in Ellesmere Port in 1964, and has been responsible for all Viva models, the Chevette and all six Astra models from 1982.
An average of 100,000 units has left the plant in each of the last 50 years.
Ellesmere Port plant director Stefan Fesser attributes some of the plant’s success to a famously robust test-driving system conducted by an employee known as Ellesmere Pete.
Mr Fesser said: “After fifty years, he still does a fantastic job of validating the great quality that comes with every car we produce. Long may he continue.”
The Ellesmere Port workforce of almost of 1,800 is gearing up for production of the new Astra next year, which will see the plant take on an additional 300 staff as part of a £140m investment by parent company General Motors.
The plant has weathered a number of motor industry storms over the years and was saved from closure in the summer of 2012 thanks to a long-term deal with unions over wages and conditions.