- nigger
- nigger-head
- nightjar
- nikau
- nipper
- nobbler
- nobblerise
- noddy
- nonda
- noogoora bur
- noon-flower
- Norfolk Island Pine
- note
- notornis
- notoryctes
- nugget
- nuggety
- nulla-nulla
- nut
- nut, bonduc
- nut, burrawang
- nut, candle
- nut, nicker
- nut, Queensland
- nut, union
- nut-grass
- nutmeg, Queensland
- nut-palm
- oak
- oak-apple
- oamaru stone
- oat-grass
- oat-shell
- oats, wild
- officer plant
- 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