A seat attachment structure of a saddle riding vehicle, in which, in a state a first end side of a seat, on which an occupant sits, in a forward/rearward direction of a vehicle body is locked to the vehicle body, a second end side of the seat in the forward/rearward direction of the vehicle body is coupled to the vehicle body, the seat attachment structure of the saddle riding vehicle comprising: a seat attachment member interposed between the second end side of the seat and the vehicle body and configured to couple the second end side of the seat to the vehicle body, wherein the seat attachment member includes: a vehicle body-side connecting section (42u, 42l, 60S-2u) swingably attached to the vehicle body while having an axis extending along a vehicle width direction as a swing axis; and a seat fixing section (39, 40) disposed at a position separated from the vehicle body-side connecting section (42u, 42l, 60S-2u) in the forward/rearward direction of the vehicle body and to which the second end side of the seat is attached; the seat attachment structure being characterized in that: the seat attachment member has left and right front protrusion sections (60S-2) having substantially horizontal upper walls (60S-2u), the vehicle body-side connecting section (42u, 42l, 60S-2u) comprises upper and lower rubber bushes (42u, 42l) disposed to overlap upper surface sides and lower surface sides of the upper walls (60S-2u) of the front protrusion sections (60S-2),and portions of the upper walls (60S-2u) of the left and right front protrusion sections (60S-2) are attached to the vehicle body together with the upper and lower rubber bushes (42u, 42l) in a state so as to be swingable in a gravity direction using an axis in the vehicle width direction as a swing axis. a seat attachment member interposed between the second end side of the seat and the vehicle body and configured to couple the second end side of the seat to the vehicle body, wherein the seat attachment member includes: a vehicle body-side connecting section (42u, 42l, 60S-2u) swingably attached to the vehicle body while having an axis extending along a vehicle width direction as a swing axis; and a seat fixing section (39, 40) disposed at a position separated from the vehicle body-side connecting section (42u, 42l, 60S-2u) in the forward/rearward direction of the vehicle body and to which the second end side of the seat is attached; the seat attachment structure being characterized in that: the seat attachment member has left and right front protrusion sections (60S-2) having substantially horizontal upper walls (60S-2u), the vehicle body-side connecting section (42u, 42l, 60S-2u) comprises upper and lower rubber bushes (42u, 42l) disposed to overlap upper surface sides and lower surface sides of the upper walls (60S-2u) of the front protrusion sections (60S-2),and portions of the upper walls (60S-2u) of the left and right front protrusion sections (60S-2) are attached to the vehicle body together with the upper and lower rubber bushes (42u, 42l) in a state so as to be swingable in a gravity direction using an axis in the vehicle width direction as a swing axis. a vehicle body-side connecting section (42u, 42l, 60S-2u) swingably attached to the vehicle body while having an axis extending along a vehicle width direction as a swing axis; and a seat fixing section (39, 40) disposed at a position separated from the vehicle body-side connecting section (42u, 42l, 60S-2u) in the forward/rearward direction of the vehicle body and to which the second end side of the seat is attached; the seat attachment structure being characterized in that: the seat attachment member has left and right front protrusion sections (60S-2) having substantially horizontal upper walls (60S-2u), the vehicle body-side connecting section (42u, 42l, 60S-2u) comprises upper and lower rubber bushes (42u, 42l) disposed to overlap upper surface sides and lower surface sides of the upper walls (60S-2u) of the front protrusion sections (60S-2),and portions of the upper walls (60S-2u) of the left and right front protrusion sections (60S-2) are attached to the vehicle body together with the upper and lower rubber bushes (42u, 42l) in a state so as to be swingable in a gravity direction using an axis in the vehicle width direction as a swing axis. the seat attachment member has left and right front protrusion sections (60S-2) having substantially horizontal upper walls (60S-2u), the vehicle body-side connecting section (42u, 42l, 60S-2u) comprises upper and lower rubber bushes (42u, 42l) disposed to overlap upper surface sides and lower surface sides of the upper walls (60S-2u) of the front protrusion sections (60S-2),and portions of the upper walls (60S-2u) of the left and right front protrusion sections (60S-2) are attached to the vehicle body together with the upper and lower rubber bushes (42u, 42l) in a state so as to be swingable in a gravity direction using an axis in the vehicle width direction as a swing axis.