The Oakland Raiders rookie quarterback had appealed the punishment, which was related to NCAA violations he committed while at Ohio State. Pryor entered the NFL supplemental draft instead of serving a five-game ban with the Buckeyes after being involved in a cash-for-memorablia scandal that has put Ohio State under NCAA investigation.
"This smacks of a calculated effort to manipulate our eligibility rules in a way that undermines the integrity of, and public confidence in, those rules," Goodell said in his decision.
Pryor may be activated by the Raiders after their game at Houston on Oct. 9.
Several members of the NFL Players Association's executive committee had expressed concerns about Goodell suspending a player who was not yet in the league. "As we have done throughout this process, we will consult with Terrelle and support him in his decision" on what to do next, NFL Players Association spokesman George Atallah said.
The quarterback originally was barred from entering the supplemental draft, then was approved by Goodell, with the proviso he must sit out five games.
Goodell said Pryor left Ohio State "in order to avoid the consequences of his conduct while in college -- conduct to which he had admitted and for which he had accepted a suspension -- and to hasten the day when he could pursue a potentially lucrative professional career in the NFL."