Assistant head coach Glen Riddersholm has also left his position with the club.
Sporting director Ben Knapper said: “Whilst we made this appointment with a long-term focus and in line with our wider club strategy and direction, unfortunately recent results and performances have deemed it necessary for us make a change."
“I’d like to place on record our sincere thanks to Johannes and Glen. They are both fantastic people who worked tirelessly to help improve and move our football club forward."
“We all wish the two of them the best in the next stage of their respective careers.”
Jack Wilshere, assisted by Tony Roberts and Nick Stanley, will take charge of the first team on an interim basis for their two remaining Championship fixtures of the season.
The Dane was appointed in May 2024 to replace David Wagner, who had been sacked following the Canaries' play-off defeat by Leeds United.