Polycrystalline diamond composites comprise a polycrystalline diamond body having a plurality of ultra-hard discrete regions dispersed within a polycrystalline diamond second region. The plurality of discrete regions has an density different from of the polycrystalline diamond second region. A metallic substrate can be joined to the body. The discrete regions can be relatively more thermal stable than, have a higher diamond density than, and/or may comprise a binder material that is different from the polycrystalline diamond second region. Polycrystalline diamond composites can be formed by combining already sintered granules with diamond grains to form a mixture, and subjecting the mixture to high pressure/high temperature conditions, wherein the granules form the plurality of discrete regions, or can be made by forming a plurality of unsintered granules, combining them with diamond grains to form a mixture, and then subjecting the mixture to first and second high pressure/high temperature conditions.