Nepenthes leonardoi is endemic to the Philippine island of Palawan. It has only been recorded from the upper slopes of a single mountain system centred on Schom-carp Peak (also known as Shumkat Peak or Shumkak Peak); it grows on the peak itself as well as on its eastern ridge, which extends in the direction of Narra municipality. The presence of this species on the easterly ridge connecting Schom-carp Peak with the Brow Shoulder massif could not be confirmed by the describing authors, but they suggested it is likely to grow there and possibly on the massif itself. The altitudinal distribution of N. leonardoi ranges from at least 1300 m above sea level to the summit of Schom-carp at 1490 m. The only known population numbers several thousand individuals.