A rotary connector device includes a rotation body and a fixed body that engage with each other in a relatively rotatable manner, in an interior thereof, a housing space having a cylindrical shape, and a flat cable housed in the housing space in a wound manner, wherein the rotation body includes: a rotating-side ring plate having an annular shape and an inner-circumferential cylindrical portion having a cylindrical shape; the fixed body includes: a stationary-side ring plate having an annular shape and an outer-circumferential cylindrical portion; the flat cable has a first end coupled to a stationary-side connector; the fixed body includes an insertion portion from the housing space toward an outer side of the fixed body along a rotation axis direction of the rotation body that relatively rotates; and the stationary-side connector is disposed on a main surface of the stationary-side ring plate on an outer side thereof.