Abstract The expanded phthalocyanine (EPc) single‐layer sheets with embedded double transition metals (labeled as TM 2 EPc) are predicted to be a novel class of highly stable 2D materials with a series of fascinating properties by means of systematic first‐principles calculations, molecular dynamics, and Monte Carlo simulations. Excitingly, the ferromagnetic Cr 2 EPc and antiferromagnetic Mn 2 – and Fe 2 –EPc have high magnetic transition temperatures of 223 ( T C ), 217 ( T N ), and 325 K ( T N ), respectively. This makes them promising candidates for low‐dimensional spintronic applications. Unexpectedly, V 2 EPc is an antiferromagnetic metal with Dirac cone, while ferromagnetic Cr 2 EPc exhibits Dirac half‐metallicity. The ultra‐high Fermi velocities near Dirac cones render them promising candidates for applications in high‐speed nanoelectronics and spintronics. Several architectured type‐II heterojunctions show promising power conversion efficiency with maximum 25.19% for Ni 2 EPc/2H‐WSe 2 , which has great potential in excitonic solar cell applications. Diverse promising properties endow this class of materials multifunction, which paves the way towards the future applications in nanoelectronics, spintronics, optoelectronics, and photovoltaics.