The former Arsenal midfielder and U18 coach takes charge after today's sacking of Canaries manager Johannes Hoff Thorup. Thorup's No2, Glen Riddersholm has also left Carrow Road today.
Wilshere has been part of Thorup's staff and now steps up as caretaker manager to the end of the season. He will be assisted by Tony Roberts and Nick Stanley.
Norwich have two games left in their Championship campaign.
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.”