The league said the suspension will be without pay, which will cost him more than $268,000. Wisniewski won't be eligible to play for the Ducks until an April 3 game in Los Angeles.
Wisniewski hit Chicago defenseman Brent Seabrook during the second period of a game Wednesday, sending the Blackhawks' player into the glass. Seabrook was briefly unconscious and didn't play the remainder of the game.
Wisniewski was given a minor penalty for charging by game officials.
But Thursday the NHL acted with the suspension.
"Mr. Wisniewski delivered a retaliatory hit to the head of an opponent who never had possession of the puck," said NFL Senior Vice President Colin Campbell. "The fact that (he) is a repeat offender also entered into this decision."
Wisniewski was also suspended for a play in October. That suspension was for two games.