In Revelation 20, Satan is locked up immediately following Armageddon. He remains locked up throughout the thousand years, while the resurrected saints reign. After the thousand years, Satan is released for a short time to lead Gog/Magog against "the camp of God’s people, the city he loves."
Those of you that consider the thousand years figurative for the past 2,000 years, do you also believe that Satan has been locked up all this time?
And I saw an angel coming down out of heaven, having the key to the Abyss and holding in his hand a great chain. He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years. He threw him into the Abyss, and locked and sealed it over him, to keep him from deceiving the nations anymore until the thousand years were ended. After that, he must be set free for a short time. (Revelation 20:1)