Regions of Papua New Guinea
- Sisigolo
- Sisibia Creek
- Sisiarenda
- Sisia Creek
- Sisiabu Island
- Sisi
- Sisi
- Sisa River
- Sisahang Creek
- Sisagle
- Mount Sisa
- Siruwai Creek
- Sirunki Mission
- Sirunki
- Sirra
- Sirot Island
- Sirorata
- Sirokka Creek
- Sirof
- Sirodubi
- Siriwa River
- Sirius
- Sirito Creek
- Sirisiri Bay
- Sirisiri
- Sirisa
- Siriruma Creek
- Sirinumu Dam
- Sirinimbu
- Siringhai Range
- Sirin
- Sirimo
- Sirikoki
- Sirik Island
- Sirikin
- Sirigubi
- Siri Creek
- Siria Creek
- Sireru River
- Sire River
- Siremi
- Sirembi
- Sirebi River
- Siranungai
- Sira Creek
- Sipuru
- Sipupu Bay
- Sipumamu
- Sipul
- Sipoma
- Sipoi
- Siplo River
- Sipisipi
- Sipara
- Sipa
- Sipa
- Sio West
- Sio
- Siowi Creek
- Siorovi
- Sio Lagoon
- Sio Island
- Sio
- Sinup Island
- Sinungum Creek
- Sinuma
- Sinu Creek
- Sinua
- Sinkurai River
- Sinipara Island
- Sinipara
- Siningiri
- Siningere
- Sinimsigin
- Sinik River
- Sinikima
- Siniap
- Sing Singe Plantation
- Singorokai
- Singor
- Singor
- Singi Creek
- Singi
- Singgo
- Singga Creek
- Singeiapa
- Singaua Plantation
- Singaua
- Singarin
- Mount Sinewit
- Sinepara
- Sinei
- Sinei
- Sinefada Point
- Sine Creek
- Sine
- Sindeni
- Sindama
- Sindaba River
- Cape Sinclair
- Sinavi
- Sinaudo
- Sinasina Reef
- Sinasina
- Sinapa Point
- Sinapa Island
- Sinapa
- Sinanu 3
- Sinanu 2
- Sinanu 1
- Sinani River
- Sinangu
- Sinange
- Sinan Creek
- Sinanai
- Sinambila 2
- Sinambila 1
- Mount Sinakuria
- Mount Sin
- Simumu
- Simuku
- Simsim Island
- Simpson Harbour
- Simoro Bay
- Simog
- Simo
- Simmindure
- Simlindon Island
- Simitumburt Bay
- Simi River
- Simini River
- Simimla
- Similam
- Simididi
- Simia
- Simi
- Simetena
- Simegu
- Simdae
- Simbum
- Simbomie
- Simbo
- Simblangu
- Simbir
- Simbini River
- Simbini Mission
- Simbini Bay
- Simbini
- Simberi Island
- Simberi
- Simbeng
- Simbari Group
- Simbap
- Simban River
- Simbang
- Simbai River
- Simbai
- Sima Villages
- Simanoli
- Simangaui
- Simaia River
- Silver Sound
- Silur Mission
- Silup Point
- Silupa
- Silria Creek
- Silopi
- Silo Number 2
- Silo Number 1
- Silom Number 2
- Silom Number 1
- Siloia Creek
- Silo Creek
- Mount Silisigoda
- Silipwaka Island
- Silipin Island
- Silin Point
- Siling River
- Silimona River
- Silimidi
- Silimbo
- Silimate Point
- Silimate
- Silimana
- Sililio
- Sili Creek
- Silibai River
- Sileibi
- Silbianggau
- Silavuti Mission
- Silaul
- Silat River
- Silanga
- Sila Mission
- Silaliura Creek
- Silaling
- Silaliba Bay
- Silahala
- Silabob
- Sila