We fabricated micrometer-scale optical ring resonators by micromanipulation of thiacyanine (TC) dye nanofibers that propagate exciton polaritons (EPs) along the fiber axis. High mechanical flexibility of the nanofibers and a low bending loss property of EP propagation enabled the fabrication of microring resonators with an average radius (rave) as small as 1.6 μm. The performances of the fabricated resonators (rave = 1.6–8.9 μm) were investigated by spatially resolved microscopy techniques. The Q-factors and finesses were evaluated as Q ≈ 300–3500 and F ≈ 2–12. On the basis of the rave-dependence of resonator performances, we revealed the origin of losses in the resonators. To demonstrate the applicability of the microring resonators to photonic devices, we fabricated a channel drop filter that comprises a ring resonator (rave = 3.9 μm) and an I/O bus channel nanofiber. The device exhibited high extinction ratios (4–6 dB) for its micrometer-scale dimensions. Moreover, we successfully fabricated a channel add filter comprising a ring resonator (rave = 4.3 μm) and two I/O bus channel nanofibers. Our results demonstrated a remarkable potential for the application of TC nanofibers to miniaturized photonic circuit devices.Keywords: micromanipulation; nanofiber; organic dye; photonics; ring resonator;