He ran on to the stage at the Chautauqua Institution where the author was about to speak on 12 August 2022, and stabbed him more than a dozen times in front of an audience.
Following a trial in Chautauqua County Court, Matar was found guilty by a jury after less than two hours of deliberations.
A man has been found guilty of attempted murder over an attack on author Sir Salman Rushdie.
The 77-year-old British-American writer was stabbed multiple times on a lecture stage in New York in 2022.
Hadi Matar was accused of trying to kill Sir Salman.
