Manchester City have assembled the first billion-euro squad, says a report by the CIES Football Observatory.
Premier League champions City, who were bought by the Abu Dhabi United Group in 2008, have spent 1.014bn euros (£906m) on their current players.
They spent 32 times the amount Norwich have laid out, the report found.
Paris St-Germain (913m euros) and Real Madrid (902m euros) are next in the list, with Manchester United (751m euros) the second English team.
Top 10
1 Manchester City - 1.014bn
2 Paris St-Germain - 913m
3 Real Madrid - 902m
4 Manchester United - 751m
5 Juventus - 719m
6 Barcelona - 697m
7 Liverpool - 639m
8 Chelsea - 561m
9 Atletico Madrid - 550m
10 Arsenal - 498m