The present disclosure relates to a solid-state imaging device, an AD converter, and an electronic apparatus that improve a crosstalk characteristic. The AD converter includes a comparator that compares the pixel signal with the reference signal, a pixel signal side capacitor, and a reference signal side capacitor. The pixel signal side capacitor and the reference signal side capacitor are formed such that a first parasitic capacity and a second parasitic capacity are substantially the same. The present technology is applicable to a CMOS image sensor, for example.