The NHL's Department of Player Safety announced the discipline after holding a hearing with the 24-year-old Fiala.
Fiala was assessed a major penalty and a game misconduct in the second period when he sent Roy head-first into the boards during Minnesota's 5-3 victory.
The Department of Player Safety said in a video that the incident happened at "high speed" and involved Fiala "giving a direct push in the back that causes Roy to crash dangerously in the boards."
Roy was helped off the ice and was able to travel with the Kings after the contest.
Los Angeles coach Todd McLellan said after the contest that the play can be a teaching point for other players.
"It will be on multiple videos, teaching clips for young players, older players, junior players, pro players on basically what not to do," McLellan said. "I feel bad for Roysie. I don't even know if there's any intent on the Fiala thing, it just happened. But we have to know by now that we can't do that."
Roy, 25, has three assists in eight games this season. Fiala scored his third goal of the season earlier in the game. He has no assists in eight games.
According to nhl.com, Fiala will lose out on $77,586.21 in salary during the suspension with the money going into the players' emergency assistance fund.
(Field Level Media)