Alli was caught on camera raising his finger in the direction of French referee Clement Turpin during England's qualifier against Slovakia at Wembley this month and had risked a potential four-game ban.
He had said the gesture was made in jest towards his former Tottenham Hotspur team mate Kyle Walker.
World soccer's ruling body FIFA ruled on Friday that the 21-year-old's behaviour had been "offensive and unsporting" and also fined him 5,000 Swiss francs (3,853.73 pounds).
Alli, who has been named in England's squad for the next two qualifiers, will now be available to play Lithuania on Sunday week.
England lead Group F on 20 points, five ahead of second-placed Slovakia, and are one win away from sealing their spot at next year's World Cup in Russia.
(Reporting by Alan Baldwin, editing by Ed Osmond)
