ZnSn_1‐xGe_xN₂ direct bandgap semiconductor alloys, with a crystal structure and electronic structure similar to InGaN, are earth‐abundant alternatives for efficient, high‐quality optoelectronic devices and solar‐energy conversion. The bandgap is tunable almost monotonically from 2 eV (ZnSnN₂) to 3.1 eV (ZnGeN₂) by control of the Sn/Ge ratio.