Speaking to about 200 people in Sioux City, Romney said he wanted to highlight the differences between himself and Clinton, the front-runner for her party's presidential nomination.
"Her view is the old, classic, European caricature that we describe of big government, big taxation, welfare state," said the former Massachusetts governor.
"She gave a speech a couple of days ago and laid out her vision for America. And as I listened to her I figured her platform wouldn't even get her elected in France," Romney, who was a missionary in France, said to chuckles and applause.
In recent French elections, conservative Nicolas Sarkozy captured the presidency, defeating Segolene Royal in her bid to become France's first female president.
Romney criticized Clinton's effort as first lady to enact universal health care and touted his success in passing a plan in Massachusetts. Although Romney won bipartisan praise for his state effort, he hasn't mentioned it much in his bid for president.
"The first difference is mine got passed and hers didn't," he said.
Romney said the election of Clinton as president would force the country to veer off course economically, militarily and socially.
"I'm convinced if Hillary were president ... that we would see instead of a stronger military and a stronger economy and stronger families, we'd see a weaker military because she would ... be able to spend money on the social programs that she favors," he said. "We'd see a weaker economy because she'd raise taxes and we'd have less money going into the private sector and creating new jobs. We'd see weaker families as well."
A Clinton campaign spokesman declined to respond to Romney's comments.
Contrasting himself with Clinton, Romney also reiterated his support for a constitutional amendment against gay marriage. Clinton has said she wouldn't support such an amendment.