Yes, according to the book. Read all of chapter 20 in Revelation, those "dead" who are judged are both those who had died in unbelief as well as the unsaved that came through the Great Tribulation and happens after the thousand year reign of Christ. Read the verses before the passage you quoted:
Revelation 20:1-6
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. I saw thrones on which were seated those who had been given authority to judge. And I saw the souls of those who had been beheaded because of their testimony for Jesus and because of the word of God. They had not worshiped the beast or his image and had not received his mark on their foreheads or their hands. They came to life and reigned with Christ a thousand years. (The rest of the dead did not come to life until the thousand years were ended.) This is the first resurrection. Blessed and holy are those who have part in the first resurrection. The second death has no power over them, but they will be priests of God and of Christ and will reign with him for a thousand years.
Those unsaved were not judged until the thousand years was over, and that is who verses 11-15 is speaking of, their final judgment:
Revelation 20:11-15
Then I saw a great white throne and him who was seated on it. Earth and sky fled from his presence, and there was no place for them. And I saw the dead, great and small, standing before the throne, and books were opened. Another book was opened, which is the book of life. The dead were judged according to what they had done as recorded in the books. The sea gave up the dead that were in it, and death and Hades gave up the dead that were in them, and each person was judged according to what he had done. Then death and Hades were thrown into the lake of fire. The lake of fire is the second death. If anyone’s name was not found written in the book of life, he was thrown into the lake of fire.
Those who die in unbelief before the Millennium starts will go to Hades/Sheol (Hell has not been created yet) just as all those who had died in unbelief before Jesus arose (remember the "rich man and Lazarus" story. They are held until the final judgment called the Great White Throne Judgment. No saved endure this judgment. Those who are condemned face the "second death" when they are cast into the lake of fire along with "death" and "hades" as well as Satan, his angels, the Beast, False Prophet and the Anti-Christ FOREVER.
Why; if ONLY the non-Christian is there at this 'judgement'?