Island

An island was an area of land completely surrounded by water, but smaller than a continent. They were common on many M-class planets.

One particular type of island was the atoll. (VOY: "The 37's")

In 2063, Zefram Cochrane claimed that he built his ship, the Phoenix, so that he could retire to a tropical island full of naked women. (Star Trek: First Contact)

In 2267, Trelane referred to his habitation as "an island of peace on my stormy little planet of Gothos." (TOS: "The Squire of Gothos")

Southern Islands

The planet Terra Nova had three large islands to the south, called continents by Humans. This was the place to which the Novans were resettled as it was unaffected by the irradiated debris from the 2083 asteroid impact. (ENT: "Terra Nova")
Following the death of Kai Opaka in 2369, widespread turmoil broke out on Bajor which by early 2370 had gone from bad to worse. There were reports of factional fighting in half a dozen districts as well as religious riots spreading throughout the southern islands. Kira Nerys established these facts while attempting to persuade Benjamin Sisko that Li Nalas should be resuced from Cardassia IV. (DS9: "The Homecoming")

Geographical features on Bajor
Land formations	Bajoran outback Dahkur Hills Janitza Mountains Northern peninsula Northwest peninsula Perikian Peninsula Southern islands Trilar Peninsula
Forests	Bestri Woods Southern Jungles
Rivers	Glyrhond River Holana River Yolja River
Geological features	Cliffs of Undalar Fire Caves Kendra Valley Kola Mountain Labyrinth Ratosha Pass Sahving Valley Serpent's Ridge Tanis Canyon
Districts	Northeastern District Northwestern District
Provinces	Dahkur Ducrain Eastern Hedrikspool Hill Jalandra Janitza Kendra Lonar Province Lotha Musilla Navot Paqu Rakantha Tozhat Wyntara Mas
Cities or villages	Bajor Hathon Ilvia Jalanda City Janir Jo'Kala Kran-Tobol Lasuma Tamulna Tempasa Unnamed
Shrine or historical sites	B'hala Batal Calash Monastery Dakeen Monastery Elemspur Gallitep Golian H'erat Karnoth Kenda Shrine Kiessa Monastery Monastery of the Kai Musilla University Qui'al Dam Relliketh Singha Sirah Temple of Iponu University of Bajor