P. olivaceus

P. olivaceus may refer to:


 * Panaeolus olivaceus, a mushroom species
 * Paralichthys olivaceus, the olive flounder, a flatfish species
 * Phylloscopus olivaceus, the Philippine leaf warbler, a bird species
 * Picumnus olivaceus, the olivaceous piculet, a bird species
 * Prionochilus olivaceus, the olive-backed flowerpecker, a bird species
 * Pristimantis olivaceus, a frog species
 * Psophodes olivaceus, the eastern whipbird, a bird species