Carbenes are pivotal reactive intermediates for accessing a wide range of complex molecules, which are frequently used in chemical synthesis and medicinal advancement. We have developed a convenient approach to fluorenes from α‐biaryldiazoacetates via low‐energy blue light‐induced photochemical generation of a carbene intermediate, where the reaction took place at room temperature without any catalysts, bases, or oxidants in acetonitrile. The present catalyst‐free and operationally simple approach enables highly efficient annulation of α‐biaryldiazoacetates under mild reaction conditions. [ABSTRACT FROM AUTHOR]