Uniper SE is a German multinational energy company based in Düsseldorf, Germany, which has been a state-owned enterprise since late 2022.

[9] Uniper was one of the financiers of the Nord Stream 2 project, which the German government suspended two days before the 2022 Russian invasion of Ukraine.

[5] It took place through a retrospective transfer of Uniper's business to 195 million new shares created by an increase in noncash capital as of January 1, 2016.

The Uniper share of 25% was sold for €1.749 billion, plus the transferred liquid funds to the Austrian OMV Group.

[23] In July 2022, the German government and Fortum agreed to bailout Uniper a €15 billion rescue deal after being severely affected by reduced supplies and high prices following the energy standoff with Russia.

[24] Germany agreed to pay €267 million for a stake in the ownership of Uniper, while also offering the firm up to €7.7 billion in financing.

[25] Under the bailout, a record in German corporate history, the government will take a 30% stake in Uniper, reducing the ownership of Fortum to 56%.

[26] In 2022 Uniper filed a lawsuit against Russia’s Gazprom, claiming €11.6 billion for damages following shortfalls and breach in gas supply under their long term contract.

[27] On 20 September 2022, Bloomberg News reported that the German government intended to nationalize the company, purchasing the remainder of Fortum's stake and becoming Uniper's sole owner.

[11] It was reported in October 2022 that Uniper was "shutting half the office space in its headquarters and lowering temperatures in areas remaining open to save gas" as it struggled to stay afloat ahead of its impending nationalisation.

According to the 2017 Sustainability Report, the power production (totalling 120.8 TWh in 2017) by primary energy source was:[41] The supervisory board consist of twelve members.

The employee representatives in 2022 were Harald Seegatz (deputy chairman), Holger Grzella, Diana Kirschner, Victoria Kulambi, Magnus Notini and Immo Schlepper.

[42] In January 2023 Uniper announced that Klaus-Dieter Maubach used his right of cancellation and would quit as CEO in March that year.