- old chum
- old-hat
- old hat
- old lady
- old man
- old-man fern
- old-man salt-bush
- old-wife
- olive, mock
- olive, native
- olive, spurious
- on
- onion, native
- onychogale
- opossum
- opossum-mouse
- opossum-tree
- orange
- orange, mock
- orange, native
- orange, wild
- orange-gum
- orange-spotted lizard
- orange-thorn
- orange-tree
- organ-magpie
- organ-bird
- ornithorhynchus
- orthonyx
- osprey
- ounce
- out-station
- overland
- overlander
- owl
- owl-parrot
- oyster
- oyster-bay pine
- oyster-catcher
- pa
- pachycephala
- packer
- paddock
- paddy lucerne
- paddymelon
- paddymelon-stick
- pah
- pake
- pakeha
- palberry
- palm, alexandra
- palm, black
- palm, cabbage
- palm nut
- palm, walking-stick
- panel
- pan-out
- pan-wash
- pan-off
- pan
- pannikin
- pannikin-overseer
- pannikin-boss
- papa
- paper-bark tree
- paper-fish
- paradise, bird of
- paradise-duck
- paradoxus
- paramatta
- pardalote
- pardalotus
- parera
- parra
- parrakeet
- parrot-bill
- parrot-fish
- parrot-perch
- parrot's-food
- parsley, wild
- parsnip, wild
- parson-bird
- partridge-pigeon
- partridge-wood
- passion-flower, native
- pastoralist
- patagorang
- pataka
- patiki
- patriot
- patter
- patu
- paua
- payable
- pea, coral
- pea, darling
- pea, desert
- pea, flat
- pea, glory
- pea, heart