The decision comes less than a week after Poile said he was not "contemplating making any coaching change at this time" during an interview by the Midday 180 Show on 104.5 The Zone in Nashville.
"Time is running out," goalie Pekka Rinne said. "You've got to change the way you do things. I think just the bottom line is enough talking. We've got to start playing."
Hynes was 150-159-45 in five seasons with the Devils and was the fifth longest-tenured coach in the NHL since he was hired June 2, 2015 when he was fired by New Jersey on Dec. 3, exactly 11 months after it signed him to a new multiyear contract.
Laviolette spent the past six seasons as coach of the Predators, going 248-143-60 in 451 regular-season games and helping them advance to the Stanley Cup Final for the first time in their history in 2017, when they lost to the Pittsburgh Penguins in six games.
"Obviously I think it was a shock to everyone," Predators captain Roman Josi said. "It's always sad to see guys like [Laviolette] and [McCarthy] go. They're great coaches but they're great people too, so I think you build a relationship with them over the years. I think they took this organization and this team to new heights over the past couple years. I think that's why you take a lot of responsibility."
Laviolette is 637-425-123 with 25 ties in 18 NHL seasons with the Predators, Philadelphia Flyers, Carolina Hurricanes and New York Islanders. He won the Stanley Cup as coach of the Hurricanes in 2006 and advanced to the Cup Final with the Flyers in 2010, losing in six games to the Chicago Blackhawks.