A novel and efficient synthesis of highly functionalized and diverse biaryls via mild base-promoted transition-metal-free benzannulation was achieved in good yield from readily available β-ketoesters, β-ketoamides, or 1,3-diketones with cinnamaldehydes or aryl aldehydes. This transformation comprises a sequence of the formation of three new bonds through multicomponent reactions as a one-pot procedure. This novel biaryl formation proceeds through domino Michael addition/intramolecular and intermolecular aldol/[1,5]-hydrogen shift/tautomerization. This protocol provides a great advantage in introducing various functional groups on the aromatic ring of biaryls.