An air-fuel ratio control apparatus includes a catalytic converter disposed at a position downstream of an exhaust gas aggregated portion; a downstream air-fuel ratio sensor disposed in an exhaust passage at a position downstream of the catalytic converter; first feedback amount updating means for updating a first feedback amount to have an output value of the downstream air-fuel ratio sensor coincide with a target downstream-side air-fuel ratio based on the output value of the downstream air-fuel ratio sensor; and a learning means for updating a leaning value of the first feedback amount in such a manner that the leaning value brings in a steady-state component of the first feedback amount based on the first feedback amount.