David Wagner is the new head coach of the Canaries.
Dean Smith was dismissed the day after his side's defeat at Luton Town.
After guiding the Terriers to promotion to the top flight in the summer of 2017, he and the club mutually agreed to part ways in the winter of 2019.
"This is a very special and proud moment," he told the club website.
It's a huge honor to be the head coach of the city.
I'm very happy with what I've seen so far. The training centre has top class facilities. We now have to work hard.
This is a new challenge for everyone. Is it going to be hard? It is not possible to say yes. The past needs to be left behind. We need to be together if we want to succeed. Together as a group of people.
Andrew Hughes, the Canaries loan player manager, will become the first team coach.
He was the boss of Young Boys in Switzerland. His time in Bern lasted eight months and included a win against Manchester United and a second place finish in the Swiss title race.
He lasted just one full season as the boss of Schalke, who finished in the bottom half of the league.
He was fired just two games into his second season after a loss to Werder.
The German-born former United States international will work with the Canaries sporting director who brought him to the club in 2015.
Since mid-December, the Canaries have collected just one point from a possible 12 in the Championship.
Despite the poor run, which has seen them win just one of their five games since the World Cup break, they are just three points outside the play-offs.
After winning the Championship title in two of the past three seasons, it was no surprise that the Canaries were the favorites to return to the top flight after being demoted last season.
When they were bottom of the league after 11 games, Daniel Farke was fired.
They finished 20th and were demoted to the second tier.