Sen. Sanders, I-Vt., incorrectly characterized Warren as a true capitalist, Pirro claimed Monday on "The Five."
Speaking about Warren's Accountable Capitalism Act, Pirro said she believed the Democrat's claim to be a capitalist is unfounded.
"What she wants to do is she wants shareholders and customers and employees to make the decisions of the corporation," Pirro said.
Pirro also claimed Warren wants to use shareholder profits to support social justice and environmental protection.
"What she's looking to do is change everything. The last thing this woman is is a capitalist," she said.
In an interview, however, Sanders criticized Warren, saying she is a capitalist, but he himself is not.
"There are differences between Elizabeth and myself," Sanders said during an interview Sunday on ABC’s "This Week." "Elizabeth I think, as you know, has said that she is a capitalist through her bones. I’m not."
The comments come amid a rise in socialism in the Democratic Party, as candidates become more willing to openly embrace socialism over capitalism. It also follows polling showing that Democrats now view socialism more positively than they do capitalism. Last year, when asked if she was a capitalist, Warren reportedly said, "I am a capitalist to my bones."
On "The Five," host Greg Gutfeld echoed Pirro's remarks, saying the attack is actually a compliment.
"That is the best thing that has been said about her all year," he quipped.