If Sherman had lost his case, he would have missed the team's final regular season game against the Rams on Sunday and possibly three playoff games.
"Thank you @nfl for upholding the truth! To the 12s Thank you your faith is rewarded! Thank you lord," he tweeted.
Seahawks Coach Pete Carroll congratulated Sherman.
"Congrats to Richard Sherman for winning his appeal! Happy for him & it'll be great to have him with us as we move forward," Carroll tweeted.
Sherman, the Seahawks' best cornerback, tested positive for performance enhancing drugs last month. Sherman appealed the result, arguing that there were mistakes made by the tester.
The Seahawks' Brandon Browner, who also failed a drug test last month, initially challenged his suspension but then dropped his appeal.
Browner began serving the punishment in Week 14. His suspension concludes after Sunday's game.