jats:titleAbstract</jats:title>jats:pLayered Ruddlesden‐Popper‐type (2D) metal‐halide perovskites exhibit markedly increased exciton binding energies, exceeding 150 meV, compared to their 3D counterparts. Many‐body physics, enabled by Coulomb interactions, plays a strong role and raises the biexciton binding energy to 50 meV. Here, photoluminescence at a range of temperatures and carrier concentrations in thin films of the layered perovskite material (Cjats:sub12</jats:sub>Hjats:sub25</jats:sub>NHjats:sub3</jats:sub>)jats:sub2</jats:sub>PbIjats:sub4</jats:sub> is reported. Biexcitons are directly observed up to a sample temperature of 225 K. An optical microcavity (comprising a distributed Bragg reflector and a metal mirror), with photonic resonances tuned near to the biexciton energy, is constructed. Optically‐pumped biexciton lasing up to 125 K, with a threshold peak excitation density of 5.6 × 10jats:sup18</jats:sup> cmjats:sup−3</jats:sup>, is observed. The demonstration of biexciton lasing above liquid nitrogen temperatures is a crucial step for the application of layered perovskites in photonic applications.</jats:p>