Candidates for the award, which is organised by the Ruter Dam female management development foundation, are chosen from Swedish companies with an annual turnover of more than 3 billion kronor.
"I am proud of winning the prize. Ruter Dam's work, with its focus on business-mindedness, quality, the long term and diversity fits in with my style of leadership," said Mia Brunell.
As managing director of Kinnevik, which owns shares in companies such as Tele2, Modern Times Group and Metro, Forsell holds one of Sweden's top jobs. The company has an annual turnover of around 80 billion kronor and employs 25,000 people in more than 60 countries.
"Mia Brunell was the jury's unanimous choice," said Gunilla Arhén, the founder of Ruter Dam.
"Many companies say that they would gladly see a woman in the most senior jobs. But sometimes they tend to waver when it comes down to it. Mia Brunell is evidence of the opposite."
Brunell has worked within the Kinnevik group for fourteen years. But she said that she had no plans to go into business when she was younger.
"When I was at university my plan was to be a journalist. I've never planned my career. It has more been the circumstances which have been decisive. You are confronted by choices the whole time," she said.
Brunell said that her curiosity is one of the characteristics that make her a good boss:
"You also have to be engaged and interested. Then it's also important to be sharp - especially at Kinnevik where there are so many different operations."
Previous winners include the managing director of IKEA Sweden, Jeanette Söderberg, the vice managing director of ICA, Ingrid Jonasson Blanck, and Marie Erling, who was head of SAS.