[Object] To propose a solid-state imaging element, an imaging device, and a method for manufacturing a solid-state imaging element that are capable of providing a pixel with polarization sensitivity while suppressing the reduction in sensitivity to non-polarized incident light. [Solution] A solid-state imaging element according to the present disclosure includes: a light receiving element included in a plurality of pixels; and a groove section provided on surfaces of at least some of the pixels in the light receiving element and extended along a prescribed direction. Two or more directions including at least mutually orthogonal two directions exist as a direction in which the groove section is extended.