The model and actress clashed with Meghan McCain - the daughter of former Republican presidential nominee John McCain - on talk show The View.
Anderson, one of Assange's most high-profile supporters, told the program the hacker's health has deteriorated since he was dramatically dragged out of the Ecuadorian embassy in London in April.
Pamela Anderson has supported WikiLeaks founder Julian Assange again. Source: The Project
He is serving a 50-week jail term for breaching bail in 2012 to avoid extradition to Sweden, where he was wanted in connection with sexual offences allegations.
Anderson, who visited Assange in Belmarsh prison in May, said: "It's devastating that people have fallen for this smear campaign, especially in America.
"I feel like an outsider looking in, looking at how America has embraced all this propaganda, it's really frustrating. I just hope he doesn't get extradited, I don't think he'll make it."
Wikileaks Founder Julian Assange leaves Southwark Crown Court in a security van. Source: Getty Images Europe
She said he has been imprisoned "to shut him up" and contested McCain's assertion that he is a "cyberterrorist".
Former Baywatch star Anderson said Assange "believes in justice" and wanted to put an end to wars by leaking classified information.
She also denied Assange is a Donald Trump supporter after The View co-host Joy Behar said he was responsible for the leaking of private conversations involving former Democratic presidential nominee Hillary Clinton.
An increasingly animated McCain said Assange's work put US lives in danger.
As Anderson issued another defence of Assange, McCain added: "He's a cyberterrorist. I'll say it. I'm not going to stand by this, it's ridiculous."
Assange is currently fighting extradition to the US where he faces 18 charges, including allegations of conspiring with intelligence analyst Chelsea Manning to hack into a classified Pentagon computer.
Then Home Secretary Sajid Javid signed off an extradition request from the US and a full court hearing is due to take place in February next year.
Julian Assange gestures as he arrives at Westminster Magistrates' Court following his arrest Source: AAP
An investigation has also been reopened into an allegation of rape in Sweden, which Assange has always denied.
