Castro, who is 81 and in poor health, announced his retirement as president of Cuba this week, ending a half-century of autocratic rule.
"I got some great news today because I was trying to figure out how I was going to get Castro into the Oscars and for me he resigns today so he can come to L.A. and go as my guest and perhaps give the acceptance speech," Moore told AP Television on Tuesday night.
"As long as he keeps it under five hours. I'm telling you, that's got to be a ratings grabber. Can you imagine him? Showing up? If I could talk to (Oscar producer) Gil Cates and maybe get Castro in a dance number at the beginning of the show? Great."