The Top 20 Euro Football Clubs Ranked by Average Match Attendance in the 2012/13 Season

It comes as a bit of a surprise to see Borussia Dortmund at the top of the list. Their Westfalenstadion (Signal Iduna Park for sponsorship reasons) can fit up to 80,645 people for league matches and according to the numbers below, it is nearly filled to capacity all season long.
It is also surprising to see four German and zero Italian teams in the top 10.
Here is the full list:
1. Borussia Dortmund - 79,893
2. Manchester United - 75,530
3. Barcelona - 71,235
4. Bayern Munich - 71,103
5. Real Madrid - 65,268
6. Schalke 04 - 61,016
7. Arsenal - 60,080
8. Hamburger - 52,829
9. Manchester City - 46,970
10. Liverpool - 44,758
11. AC Milan - 44,123
12. Paris Saint-Germain - 43,239
13. Internazionale - 42,097
14. AS Roma - 42,062
15. Chelsea - 41,462
16. Fenerbahce - 40,895
17. Galatasaray - 39,093
18. Atletico Madrid - 37,956
19. Tottenham - 36,151
20. Juventus - 35,973
The largest stadium in Europe, in terms of capacity, is FC Barcelona's Camp Nou, which seats 99.786 people.