The word "beatitude" means supreme blessedness, exalted happiness, or utmost bliss. Most often we use "The Beatitudes" to refer to Jesus's nine declarations of blessedness (beginning "blessed are") in the Sermon on the Mount (Matthew 5:3-11). There are also seven statements of blessedness in the Book of Revelation.
Revelation 1:3 Blessed is he that readeth, and they that hear the words of this prophecy, and keep those things which are written therein: for the time is at hand.
Revelation 14:13 Blessed are the dead which die in the Lord from henceforth: Yea, saith the Spirit, that they may rest from their labours; and their works do follow them.
Revelation 16:15 Blessed is he that watcheth, and keepeth his garments, lest he walk naked, and they see his shame.
Revelation 19:9 Blessed are they which are called unto the marriage supper of the Lamb.
Revelation 20:6 Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
Revelation 22:7 Blessed is he that keepeth the sayings of the prophecy of this book.
Revelation 22:14 Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city.
* I first noticed "The Seven Beatitudes of Revelation" in an article of the same title by Jerry H. Wilson (Gospel Light, July 1978).