The district court in Varberg, on Sweden's south-west coast, sentenced the 26-year-old to three years' imprisonment for breach of copyright law and gross money laundering.
Another man, a 23-year-old, received a conditional sentence and has to take part in community service for copyright infringement.
The Swefilmer streaming website, which was closed down in 2015, was one of the most popular sites in Sweden for streaming films illegally, sparking fierce criticism from the film industry.
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The trial in Varberg's district court covered more than 1400 films considered by the prosecutor to have been made available illegally through the site.
Neither of the two men will have to pay damages to the film distribution companies, but the 26-year-old faces a fine to the Swedish state of 14 million kronor ($1.59 million) for income from criminal activities, for instance from advertising revenues from the website.
Meanwhile, websites with similar names are still available online, and the film companies' representative Rättighetsalliansen (Rights Alliance) is critical of the Swedish authorities for reacting too slowly to online pirating activities.