An amplifier circuit includes: plural transistors; plural first transmission lines respectively connected between input terminals of the plural transistors; plural second transmission lines respectively connected between output terminals of the plural transistors; an input node connected to the input terminal of a first stage transistor among the plural transistors; an output node connected to the output terminal of a final stage transistor among the plural transistors; and a capacitance connected to the output terminal of the first stage transistor via a third transmission line.