Provided is a solid-state image pickup apparatus, including: a pixel region, in which a plurality of pixels each including an amplifier transistor are arranged two-dimensionally in rows and columns, and which includes an n-row signal mixing region in which outputs of n amplifier transistors are mixed, where n is a natural number of 1 or more, and an m-row signal mixing region in which outputs of m amplifier transistors are mixed, where m>n; a column signal line to which a voltage from the amplifier transistor is output; and a clipping circuit, which is configured to clip a voltage in the column signal line, and is arranged at a position that is closer to the n-row signal mixing region than to the m-row signal mixing region.