The British rock star was talking to Rolling Stone magazine when he said: "Please, please don't vote for Mitt Romney. F**k him. Repeal abortion law is the first thing he'll do. F**king monster."
On the topic of Barack Obama, Lemmy protested: "They're trying to drag him down now. I mean, the poor f**ker's only just gotten rid of all that George Bush s**t that he left, or is trying to.
"And he's being stonewalled by the f**king Congress all the time. I don't know how he's gotten anything done. They should be glad. I mean the alternative is Mitt Romney."
The vocalist and bassist of rock band Motörhead was previously a member of Hawkwind and the subject of eponymous 2010 documentary Lemmy, which featured interviews with musicians including Dave Grohl, Slash, Alice Cooper and Mick Jones of The Clash.
Polling stations have today (November 6) opened for US voters, with the presidential election result likely to be announced on Wednesday, November 7.