Pep Guardiola's side scored over 100 goals in a single league season for the third time, picking Norwich apart at will.
The visitors could have levelled through Teemu Pukki, but after racing through on goal, he was denied expertly by Ederson.
With the clock ticking over into first-half stoppage time, De Bruyne made it two, curling a spectacular shot into the top corner from 20 yards.
Raheem Sterling latched onto De Bruyne's pass and netted his 20th league goal of the season and our third of the afternoon with just over ten minutes remaining, making the Belgian equal the Premier League's assist record.
Skipper David Silva was applauded off the pitch late on in his final league appearance for City, but with City still contesting in the UEFA Champions League, the Spaniard will be given a fitting tribute after his final ever display for the Club.
View the best images from the victory via the gallery below.