It said several of Samsung's devices had infringed iPhone-maker Apple's software and design patents.
The jury rejected Samsung's claims that several of its patents had been breached and awarded it no damages.
"We will move immediately to file post-verdict motions to overturn this decision in this court and if we are not successful, we will appeal this decision to the Court of Appeals," a statement from Samsung said.
Apple and Samsung account for more than half of global smartphone and tablet computer sales.
The nine-person jury at the federal court in San Jose, California had to consider 700 questions about each side's claim that its rival had infringed its intellectual property.
It deliberated for less than three days before coming to its unanimous decisions.
It rejected the South Korean firm's claim that Apple's intellectual properties were invalid. It added that Samsung was "wilful in its infringement" in many of the cases.
Not all of Apple's claims were upheld - it had claimed a total of $2.5bn (£1.6bn) in damages. Samsung had sought $519m.
Apple said it applauded the court "for finding Samsung's behaviour wilful and for sending a loud and clear message that stealing isn't right."
Samsung described the verdict as "a loss for the American consumer".
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