In triplet-triplet annihilation-based photon upconversion (TTA-UC), the utilization of near-infrared (NIR) light with a wavelength longer than 850 nm remains an outstanding issue. We realized this by employing metallonaphthalocyanines as triplet sensitizers; upon excitation of NIR light (856 nm), upconverted emission was observed in the visible range with remarkable photostability.