PROBLEM TO BE SOLVED: To provide a sensor capable of improving detection accuracy, and a sensor system.SOLUTION: A sensor 110 includes: a first light emitting region 11； a second light emitting region 12； and a light receiving element. At least any one of at least a part of first light emitted from the first light emitting region and at least a part of second light emitted from the second light emitting region is incident to the light receiving element 30. A second position of the second light emitting region in a first direction from the first light emitting region toward the second light emitting region is between a first position of the first light emitting region in the first direction and a light receiving position of the light receiving element in the first direction.SELECTED DRAWING: Figure 1【課題】検出精度を向上できるセンサ及びセンサシステムを提供する。【解決手段】センサ１１０は、第１発光領域１１と、第２発光領域１２と、受光素子３０と、を含む。受光素子には、第１発光領域から出射した第１光の少なくとも一部及び第２発光領域から出射した第２光の少なくとも一部の少なくともいずれかが、入射する。第１発光領域から第２発光領域に向かう第１方向における第２発光領域の第２位置は、第１方向における第１発光領域の第１位置と、第１方向における受光素子の受光位置と、の間である。【選択図】図１
