Are there any players who have won an NCAA football championship while playing for two different teams?
I found this answer while researching the basketball version of this question.
J.T. White won a football championship at Ohio State in 1942 and then at Michigan in 1947.
This page says the following:
Q: What college football player won national championships with two different teams?
A: According to Kent Stephens, curator at the College Football Hall of Fame:
"If you regard Michigan as claiming a piece of the 1947 title then JT White played there and at Ohio State in 1942."
Wikipedia confirms that Ohio State shared the football national championship in 1942 and Michigan shared the football national championship in 1947. Wikipedia also confirms that JT White played football for Ohio State in 1942 and Michigan in 1947.