The two-game penalty for domestic abuse was widely criticized as too lenient, but Goodell stood by his decision when addressing media members Friday, a day before the Hall of Fame enshrinement ceremonies in Canton, Ohio.
"Domestic violence is not acceptable," said Goodell at the impromptu session. "We went through the process of evaluating whether there would be discipline. "What's important here is that Ray has taken responsibility for this and has been accountable for his actions."
Rice was arrested and charged with simple assault-domestic violence after video posted online by TMZ.com in February showed the running back lifting his then-fiancee out of an Atlantic City casino elevator.
In May, Rice was accepted into a pretrial intervention program that will allow him to avoid serving time in jail. The charges against him will be expunged from his record upon successful completion of the one-year program.
Rice spoke publicly about the incident and his suspension on Thursday and called his actions that night "totally inexcusable" and "something I'm going to pay for the rest of my life." He and Janay Palmer are now married.
"It's important to understand this is a young man who made a terrible mistake," Goodell added. "We're very confident that this young man understands what he needs to do to move forward."
Goodell said the two-game penalty was consistent with other punishments handed down by the league.
"Ray Rice did not have another incident. We take that into account," Goodell stated when asked to compare the penalty to others, including those that are longer for substance-abuse. "When someone has a first offense, and has a strong background ... we take that into account and when there's a pattern we take that into account.
"I take into account all the information before making a decision what the discipline would be. I had the opportunity to hear from Ray, to hear from his wife and other people and I took all that into account."