The jury upheld Apple’s claims that its rival had copied its “bounce-back” effect, which makes on screen lists ‘jump back’ as if on a rubber band, and the iPhone’s tap to zoom feature.
Samsung was also found to have infringed the patents covering the looks of the iPhone with some of its own handsets.
Awarding Apple $1bn in damages, the jury rejected counter-claims that the firm had infringed patents owned by Samsung.
In a statement Apple thanked the court “for finding Samsung’s behaviour wilful and for sending a loud and clear message that stealing isn’t right”.
The iPad and iPhone maker is now expected to seek an injunction preventing the infringing devices being imported and sold in the US.
Samsung is likely to appeal the verdict. In a statement the company said: “This is not the final word in this case or in battles being waged in courts and tribunals around the world, some of which have already rejected many of Apple’s claims. Samsung will continue to innovate and offer choices for the consumer.”