Swift accused Mueller of groping her at a meet-and-greet event in June 2013. He will be required to pay $1 in damages to Swift.
The jury, comprised of six women and two men, also found the singer's mother, Andrea Swift, not liable for tortious interference.
After the reading of the verdict, Swift embraced her mother.
In a statement, Swift thanked the judge and her legal team for "fighting for me and anyone who feels silenced by a sexual assault."