The 51-year-old told Capitol File magazine: 'She wasn't qualified to be vice president. She wasn't a qualified candidate. I think that became quite evident during the campaign."
The actress, who plays the 47-year-old in her latest film Game Change, suggested that she was more after the title than anything else when she and John McCain ran against Barack Obama.
Moore continued: "It was so shocking to me when she resigned the governorship of Alaska when the presidential election was over.
"I was stunned. I just think that shows such an unbelievable lack of interest in the actual governing."
Palin has already expressed her disappointment at the HBO Films TV movie, which will premiere March in the US.
She said: "I think I'll just grit my teeth and bear whatever comes what may with that movie. Well, I am all about job creation and I guess I could provide some of these gals who pretend like they're met with some job security.
"I would ask though that - if they're of the mind of spreading the wealth around - that perhaps they want to spring for one of my kid's braces or something as they capitalise on pretending to be me."
Moore also admitted that she only had a short while to get ready to play Palin.
She confessed: "I basically had two months to prepare, so I cleared my schedule of everything, literally. I cleared everything that didn't involve my family - I just let go of it and spent all my time doing research.
"It was total immersion. The trickiest thing is to take all these physical and vocal characteristics and somehow filter the character's essence through them. And then you personally have to meet them somewhere, too. There's this melding that has to happen."
> Sarah Palin to supporters: 'Don't waste time watching Game Change'
> Julianne Moore is Sarah Palin in new Game Change trailer - watch
Watch the Game Change trailer below: