A measurement sensor package and a measurement sensor reduce susceptibility to noise and enable highly accurate measurement. A measurement sensor package (1) includes a substrate (2), a lid (3), and a ground conductor layer (4). The substrate (2) contains a light emitter and a light receiver, and includes a substrate body (20), a plurality of ground via conductors (21), an frame-shaped ground conductor layer (22), signal wiring conductors (23), and an external connection terminal (24). The ground via conductors (21) are connectable to a ground potential, and are located outward from a first recess (20a) and a second recess (20b) included in the substrate body (20) in a plan view.