Louisville Sports Report writer Howie Lindsay was the first to spot the mistake at TD Ameritrade Park in Omaha on Sunday and upload a picture to Twitter.
The photo went viral, but the NCAA were forced to wait until later in the day to correct the sign without disrupting play.
"We now have a correct version in place for the rest of the series," said spokesman Cameron Schuh.
Vital update: The sign has been fixed. It now reads: "COLLEGE WORLD SERIES" pic.twitter.com/lzCa2Iw6WP— Howie Lindsey (@howielindsey) June 17, 2013