Yes, Stephen Colbert is Catholic. He is very Catholic (it’s an old blog, but has TONS of Catholic Colbert references). He was raised in a very Irish-Catholic household as the youngest of 13 children, was an altar boy for 12 years, and was a CCD teacher for all three of his children when they were getting ready for their first Communions (and has been willing to get, um, rather abrupt about this fact).
However, one of the most moving things I ever saw him do was when he went to Congress to talk to them about the rights of migrant workers. At the end of the testimony, Rep. Judy Chu asked Stephen, ““Mr. Colbert, you could work on so many issues, why are you interested in this issue?” Stephen’s response was: “I like talking about people who don’t have any power, and it seems like one of the least powerful people in the United States are migrant workers who come and do our work, but don’t have any rights as a result. And yet we still invite them to come here, and at the same time ask them to leave. And that’s an interesting contradiction to me, and, you know – what’s whatever you do for the least of my brothers, and these seem like the least of our brothers right now. A lot of people are ‘least brothers’ right now, because the economy is so hard, and I don’t want to take anyone’s hardship away from them and diminish anything like that. But migrant workers suffer … and have no rights.”