Wallström, one of Sweden's most popular politicians, has spent many years away from the domestic political scene but has now jumped into the Social Democrats' election campaign, working as an electioneer and with her sights seemingly set on a coveted prize - the position of foreign minister, newspaper Dagens Industri reports.
"I am interested and involved in international politics, for instance through my work in the UN," Wallström told the newspaper on Friday. "So of course I hope to participate in foreign debate as well."
The first step is to win the election.
"One can't go into it aiming for a specific post. First and foremost we have to win," she told newspaper Aftonbladet.
But should power shift to Social Democrats in the upcoming election, Wallström plans to be involved.
"What I have seen of integration and immigration politics makes me long to get my teeth into it again," she told TV4 in April. "It's a new political situation and an important moment for Sweden as a country."
In 2006 Wallström was voted the "most popular woman in Sweden", above royals, athletes, and celebrities.
When Former Prime Minister Göran Persson left office she was a popular choice for next party leader - but she made it clear she was not interested. Wallström left politics in 2012, and has been working as board chairwoman at Lund University since then.
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"It's largely Stefan [Löfven] who has motivated me," Wallström told DI of her renewed interest in politics. "Of course it's more motivating when we have a party leader I really believe in. And I also have the energy and desire to contribute."
Wallström has held many positions in Swedish and European politics, including European Commissioner for the Environment, Swedish Minister for Consumer Affairs, Minister for Culture, and Special Representative of the UN Secretary-General on Sexual Violence in Conflict. She was also the first member of the European Commission to open a blog.