Vehicle side portion structure

A vehicle side portion structure includes: a guide groove portion that extends along a vehicle front-rear direction at a side portion of a vehicle body, and that guides a sliding door so as to be capable of sliding; a door side groove portion that is formed at the sliding door, and that extends so as to be continuous with the guide groove portion in the vehicle front-rear direction in a closed state of the sliding door, and a rear camera that is disposed in the door side groove portion, and that is capable of capturing an image of a vehicle rear side.