The company has invested £100m in the site, which will now produce a number of small electric vans and passenger car variants for Stellantis' various brands.
The plant was first opened in 1962 and produced Vauxhall Astra models from 1981 until 2022. The Cheshire plant will now produce the Vauxhall/Opel Combo Electric, Peugeot e-Partner and Citroën ë-Berlingo sister models.
The Fiat E-Doblò will also be produced at the plant, due to increased demand for electric vehicles (EVs) across Europe.
From 2024, the facility will also expand its production portfolio to include a range of electric passenger vehicles, including the Vauxhall Combo Life Electric, Peugeot e-Rifter and Citroën ë-Berlingo MPVs.
"Today's announcement, in which Ellesmere Port becomes the UK's first EV-only manufacturing plant and the first Stellantis plant globally dedicated to EVs, is a very visible demonstration that this government has got the right plan for the UK's automotive sector," said Kemi Badenoch, secretary of state for business and trade.
"Alongside recent investments from other major vehicle manufacturers, we are ensuring the UK remains at the forefront of automotive innovation, as well as securing jobs in this critical industry and its wider supply chain."
The Ellesmere Port plant has undergone several key changes as part of its transformation for EV production. These include the addition of a battery assembly shop, upgraded General Assembly and relocation of the bodyshop, which has contributed to a 60 per cent reduction of the total site area for improved energy efficiency and productivity.
At 118,000m2, the entire plant is now a similar size to the previous bodyshop.
Diane Miller, plant director, Ellesmere Port, added: "The start of EV production at Ellesmere Port signals a bright future for the plant, ensuring it will continue to manufacture vehicles for many years to come.
"With Vauxhall's long history of UK manufacturing, it's especially fitting that the first electric model to roll off Ellesmere Port's production line is a Combo Electric. The welcome addition of the Fiat E-Doblò to the plant is a positive reflection of increasing electric vehicle demand."
The plant upgrade is also part of the Stellantis commitment to halve its carbon footprint by 2030, based on 2021 data, and to become a carbon-neutral firm globally by 2038. In the longer term, the plant is planned to run on solar and wind power as well as connect to the HyNet North West Hydrogen Pipeline.
In April, Auto Trader warned that the UK is in danger of "veering off-track" from the target of banning petrol cars by 2030, as the demand for new EVs slumps due to the stubbornly high cost of the vehicles. Other factors such as high interest rates and an increase in the cost of electricity also played a role, the body said.
Earlier this week, the UK's largest EV charging hub opened in Birmingham.
