His hit film Turist won in the Best Film, Best Supporting Actor, and Best Cinematography categories.
Another three awards were given to the movie for Best Editing, Best Screenplay and Best Director at a glitzy ceremony on Monday night.
No other movie has won so many prizes at the Guldbagges.
Ruben Östlund, center, alongside Turist film producer Erik Hemmendorf, far right. Photo: Photo: TT
In early January, 'Turist', known as Force Majeure abroad, was nominated in ten categories in the prestigious Guldbagge awards.
It follows a Swedish family's skiing holiday in the French Alps, exposing the conflict that emerges between a married couple after the family comes close to death.
Östlund's success came after he missed out a Golden Globe and failed to make the final shortlist for the Best Film Category at the Oscars.
"It feels great, incredibly comforting," he told Swedish media at a press conference after the Guldbagge gala.
"It's so damn nerve wrecking before they announce the winning name, and they said 'Turist' so many times," he added.
The director also said that the numerous awards came as a relief after his lack of wins abroad.
"It is clear that this is a form of revenge. If I had not won anything [tonight] then it would have been a little sour."
The 50th Guldbagge Awards ceremony, presented by the Swedish Film Institute, honoured the best Swedish films of 2014.
The ceremony was televised by SVT and was hosted for the third time by Petra Mede, a well-known Swedish comedian.