While there may be others we don't know of who God has created or will create in the future, we know the following will be in heaven: God himself (Deut. 26:15; Matt. 6:9); all God's people—covered by Christ's blood—from earth who have died (Rev. 4-5; Luke 16:22, 25; Heb. 12:23); righteous angels (Luke 2:15; Matt. 28:2; Heb. 12:22).
For more information on this subject, see Randy Alcorn's book Heaven.
Randy Alcorn (@randyalcorn) is the author of over sixty books and the founder and director of Eternal Perspective Ministries.