Was Che Guevara a catholic? I think I have read that Castro was... Strange things come out from Rome.
He made it clear that he was if anything the exact opposite of Christ, so no, more likely he’s an atheist (besides, you’d need to be an atheist to be a Marxist).
As far as Castro, he may have been raised Catholic, but his running a Marxist organization means he by that time already left the Church (we Catholics do not believe in “Once Saved, Always Saved”, at least, not as a rule. My American history teacher does claim “once catholic, always catholic”, but then again, he was a lefty who proudly admitted to partaking in the 60s revolution during my orientation).