The 3 top sporting goods brands in football: Puma, adidas, Nike invest heavily in the relationships with the clubs of the major European leagues. Thus among the top 10 biggest kit contracts there are 5 clubs from the Premier League, 2 from La Liga, 2 from the Bundesliga, and one sole from the French Ligue 1, guess whom ?
The source is the Spanish sports paper AS
So how does the list look like ?
Real Madrid is top of the list. The kit deal or the revenue generated from the kit is broken down into several pieces. The athletic apparel. Main shirt sponsor + segundary sponsor typically shirt sleeve sponsor.
In the graph kit revenues blue are plotted against the merchandise revenues red. The main take away is that clubs which have more fans will score higher on the red graph merchandise, while clubs which have more strategic importance for corporations or state actors score higher on kit revenues, the blue line.

Number 1 is Real Madrid at a total of 260m Euros a year.
adidas pays Real Madrid 120m Euros a year as their official and exclusive kit provider.
Fly Emirates pays 70m Euros a year for the privillege to hold the slot as the main shirt sponsor.
HP pays another 70m Euros a year as the shirt sleeve sponsor.
A total of 260m Euros a year that Real Madrid takes in annually. Just from their various kit deals.
Number 2 is Manchester City with a total of 210.5m Euros a year.
Puma pays 115m Euros a year
Etihad Airways pays 74m Euros a year for the main shirt sponsor slot
OKX pays 21.5m Euros a year for the left arm sleeve.
Number 3 is Manchester United at 200m Euros a year
adidas pays 105m Euros
Snapdragon pays 70m Euros a year
DXC tech pays 25m Euros a year.
Number 4 is FC Barcelona at 198m Euros
Nike pays 120m Euros a year
Spotify pays 70m a year
Ambilight TV pays 8m a year
Number 5 is PSG = 170m Euros
Nike 90m Euros
Qatar Airways 70m Euros
QNB 10m Euros
Number 6 is FC Bayern München = 137m Euros
adidas 60m
Deutche Telekom 65m
Allianz 12m
Number 7 is Arsenal = 136.6m Euros
adidas: 67m Euros
Fly Emirates: 58m Euros
Visit Rwanda: 11.5m Euros
Number 8 is Liverpool FC = 105m Euros
Number 9 is Borussia Dortmund = 103m Euros
Number 10 is Tottenham = 80m Euros
and most likely those just below the top 10 are Chelsea FC, Newcastle United, Juventus, Atletico Madrid, and maybe Inter or AC Milan.