What is the largest crowd to ever watch a college football game and where did it take place?
The largest crowd to watch a regular-season college football game was composed of the 113,090 fans who watched the University of Michigan and the Connecticut Huskies on September 4, 2010, at Michigan Stadium.
Unofficially, the NCAA estimates that crowds of 120,000 people watched games involving Notre Dame and USC in 1927 and Notre Dame and Navy in 1928 at Soldiers Field in Chicago. And a confirmed 112,912 fans watched Notre Dame defeat USC at Soldier Field in 1929, which beats Michigan's record of the current era.
You can download the current NCAA record books from their site.