Methods of fabricating earth-boring tools include forming an outer portion of an earth-boring tool from a powder mixture comprising hard particles and matrix particles comprising a metal matrix material, disposing a molten material at least partially within the outer portion of the earth-boring tool, and forming the molten material into another portion of the earth-boring tool. Methods of fabricating a bit body of an earth-boring rotary drill bit include forming an outer portion comprising a plurality of hard particles and a plurality of matrix particles comprising a metal matrix material and casting a molten material at least partially within the outer portion of the bit body to form another portion of the bit body. Earth-boring tools include a body for engaging a subterranean borehole having an outer portion and an inner portion comprising at least one material solidified within a cavity formed within the outer portion.