Millions of “Dancing with the Stars” fans have seen Ralph Macchio cutting a rug – but has he been wearing one too?

That’s been the big question since the well-coiffed former “Karate Kid” star first fox-trotted across the “DWTS” stage with pro partner Karina Smirnoff.

Speculation is running rampant among stars and fans alike that the 49-year-old actor is doing his two-step under a toupee!

Rosie O’Donnell posted on Twitter during the East Coast airing of the show: “karate kid ? ralph m – real hair?…i think he did great…it looks like a weave.”

Late-night talk-show host George Lopez quipped: “He cut a mean rug, then took the rug that he cut, glued it to his head!”  

An anonymous Internet poster weighed in on the follicular mystery, stating: “I saw him up close last year at an event & can confirm he wears hair plugs. Sad but hey that’s life!”

Another online observer added: “He wears a hairpiece – and a bad one at that – I think he must’ve got some bad advice from Chuck Norris – looks like there’s a dead cat on HIS head!”

A source close to Ralph – who’s getting good scores with Karina early in the competition – says his hair is real, but that the actor often combs it over on his forehead to hide a receding hairline.

“It makes his thatch look thicker, especially on television!” joked the source. “He really is very vain.”

Ralph’s rep Jill Fritzo did not split hairs when The ENQUIRER asked her to clear up the mystery.

Regarding all the toupee tittle-tattle, she laughed and responded: “One hundred percent untrue. It’s just the way Ralph’s hair was styled.”