Transition metal‐catalyzed direct C−H bond functionalization of heterocycles with halo(het)arenes has received considerable attention as synthetic alternative to standard cross‐coupling reactions regarding step‐ and atom‐economy in the preparation of heteroarylmetals intermediates and better chemo‐selectivity towards standard organic functions such as aldehyde, ketone, ester, cyanide, and amide. An additional major and poorly highlighted interest of such methodology is its unparalleled ability to open the chemical space of functionalization of heterocycles towards challenging unprecedented sites. This Review gives an overview of the advances in challenging orthogonal direct C−H arylation of heterocycles related to the wide variety of catalytic C−H bond metalation processes, most of them evaluated by DFT calculations.