A rotary connector device, wherein: a stator and a rotator, which rotates with respect to the stator concentrically with a steering, are formed; a torque transmitting portion is formed, which is located on a radially internal side of an angle detection rotating body concentrically therewith, is formed into a substantially tubular shape and elongated downward from a lower end of an inner peripheral tube portion of the rotator, rotates together with the rotator, and transmits a rotation torque of the steering to the angle detection rotating body, the angle detection rotating body being located concentrically with a rotation axis of the steering on an inner peripheral side of an angle detection sensor, the angle detection sensor being formed into a ring shape in a plan view, being mounted concentrically with the rotation axis of the steering, and detecting a rotation angle of the steering; fitting portions for fitting to fitting allowance portions, which are formed on at least parts of a circumferential direction of the angle detection rotating body, are formed on the torque transmitting portion; the fitting portions are each formed into a trench shape notched so as to divide a circumference of the substantially tubular-shaped torque transmitting portion along an axis direction of the steering; the fitting allowance portions include fitting protrusions which protrude radially inward so as to fit to the trench-shaped fitting portions on predetermined opposing portions of an inner peripheral surface of the angle detection rotating body, which oppose each other in a diametrical direction across the rotary center of the angle detection rotating body; fitting abutting portions (62t, 63t, 64t, 65t, 67t, 68t) of the fitting portions, which fit and abut against the fitting allowance portions, are formed in a shape tapered toward the fitting protrusions; and the fitting portions and the fitting protrusions abut each other at a point or along a line. a stator and a rotator, which rotates with respect to the stator concentrically with a steering, are formed; a torque transmitting portion is formed, which is located on a radially internal side of an angle detection rotating body concentrically therewith, is formed into a substantially tubular shape and elongated downward from a lower end of an inner peripheral tube portion of the rotator, rotates together with the rotator, and transmits a rotation torque of the steering to the angle detection rotating body, the angle detection rotating body being located concentrically with a rotation axis of the steering on an inner peripheral side of an angle detection sensor, the angle detection sensor being formed into a ring shape in a plan view, being mounted concentrically with the rotation axis of the steering, and detecting a rotation angle of the steering; fitting portions for fitting to fitting allowance portions, which are formed on at least parts of a circumferential direction of the angle detection rotating body, are formed on the torque transmitting portion; the fitting portions are each formed into a trench shape notched so as to divide a circumference of the substantially tubular-shaped torque transmitting portion along an axis direction of the steering; the fitting allowance portions include fitting protrusions which protrude radially inward so as to fit to the trench-shaped fitting portions on predetermined opposing portions of an inner peripheral surface of the angle detection rotating body, which oppose each other in a diametrical direction across the rotary center of the angle detection rotating body; fitting abutting portions (62t, 63t, 64t, 65t, 67t, 68t) of the fitting portions, which fit and abut against the fitting allowance portions, are formed in a shape tapered toward the fitting protrusions; and the fitting portions and the fitting protrusions abut each other at a point or along a line.