In her most outspoken allegation so far the defeated Democrat nominee said she was in "no doubt" people connected to her rival helped Russia to interfere.
Mrs Clinton was speaking as she published a 495-page book "What Happened" about the campaign. In it she savaged Mr Trump as "hateful and flagrantly sexist," a "clear and present danger to the country and the world," and a "fraud and liar" who made her skin crawl.
Speaking to USA Today about Russia links, she said: "There certainly was communication and there certainly was an understanding of some sort.
"Because there's no doubt in my mind that (Vladimir) Putin wanted me to lose and wanted Trump to win."
Asked if she believed there was collusion with Russia by Trump associates, Mrs Clinton said: "I'm convinced of it."
Mrs Clinton's comments went further than other high profile Democrats.
The question of whether there were links between the Trump campaign and Russia is being investigated by special counsel Robert Mueller and several different committees in Congress.
In her book Mrs Clinton said the Mueller investigation was "much more serious" than Watergate, and Mr Putin had a "personal vendetta" against her.
She wrote: "I wasn’t just running against Donald Trump. I was up against the Russian intelligence apparatus.
"This wasn’t the normal rough-and-tumble of politics. This was, there’s no other word for it, war."
Mrs Clinton also blamed former FBI Director James Comey for reopening an investigation into her email server days before the vote, and her Democrat rival Bernie Sanders..
She said: "There were all of these outside forces coming at me right until the very end. I didn't get anything like that respect from Sanders and his supporters and it hurt."
In her book Mrs Clinton also compared Mr Trump's approach to George Orwell's dystopian novel Nineteen Eighty-Four and the Soviet Union, saying he had conducted a "war on truth".
She wrote; "Attempting to define reality is a core feature of authoritarianism. This is what the Soviets did when they erased political dissidents from historical photos.
"This is what happens in George Orwell’s classic novel Nineteen Eighty-Four, when a torturer holds up four fingers and delivers electric shocks until his prisoner sees five fingers as ordered."
She added: "If he stood up tomorrow and declared that the Earth is flat, his counselor Kellyanne Conway might just go on Fox News and defend it as an 'alternative fact' and too many people would believe it."
Mrs Clinton, who is "done" being a political candidate, said she declined anti-depressants and therapy following her defeat but drank Chardonnay instead.
As her book was published Mr Trump wrote on Twitter: "Fascinating to watch people writing books and major articles about me and yet they know nothing about me and have zero access. FAKE NEWS!"
Sarah Sanders, the White House press secretary, said it was "sad" that Mrs Clinton was spending the last chapter of her political life making "fake and reckless attacks to prop up book sales".