An optical device ensuring projection of light over a wide range as well as reduction in size, and a mobile apparatus mounted with the optical device are provided. The optical device (100) includes a light-projecting unit (110) and a light-receiving unit (120). The light-projecting unit (110) has a projector (114) and a lenticular sheet (112) arranged in layers. First and second cylindrical lens arrays having their generatrices orthogonal to each other are formed on the respective surfaces of the sheet (112). The light-receiving unit (120) has a light-receiver (124). The light-projecting unit (110) and the light-receiving unit (120) are arranged adjacent to each other in an integrated manner so that the light-receiver (124) can sense the light emitted from the projector (114) via the sheet (112) and then reflected from an object.