Kalawao County occupies the Kalaupapa Peninsula on the north coast of Molokai, comprising just 12 square miles of land and 41 square miles of surrounding water. It is the smallest county in the United States by land area. The county has no elected officials, no county council, and no county administration in any conventional sense. Instead, it operates as a judicial district of Maui County, which governs the rest of Molokai. The Hawaii State Department of Health administers the county directly. The only county statutes that apply specifically to Kalawao are those related to health. A mayor holds nominal executive power, and a county sheriff is appointed from among local residents. The U.S. Census Bureau does not count Kalawao as having its own county government, treating it instead as a dependency of the state.

The peninsula that constitutes Kalawao County was formed geologically by a late eruption of an undersea volcano near Kauhako Crater, which sent lava spreading outward to create a low shield. This was the most recent volcanic activity on Molokai, occurring long after the massive sea cliffs behind the peninsula had formed through catastrophic erosion. Every government that has ruled Hawaii used this peninsula for the same purpose. The Kingdom of Hawaii, the Republic of Hawaii, the Territory of Hawaii, and the State of Hawaii all exiled people with Hansen's disease to this isolated strip of land, from 1866 until 1969. The cliffs, rising over a quarter-mile high, served as a natural barrier. The only land access was a mule trail. The quarantine policy was lifted only after antibiotic treatments made patients non-contagious, but by then, the peninsula's identity had been fixed for more than a century.

The numbers track a slow vanishing. In 1900, 1,177 people lived in Kalawao County, almost all of them patients exiled with leprosy. By 1950, the count had dropped to 370. By 2010, it was 90. The 2020 census recorded 82 residents. The median age was 50.3 years, and nearly a quarter of residents were 65 or older. Kalawao County has the highest Pacific Islander population percentage of any U.S. county, and is the only county where Pacific Islanders make up a plurality. Current residents include former patients who chose to remain after the quarantine was lifted, federal employees working on preservation projects within the Kalaupapa National Historical Park, and some state health workers. The state promised the former patients they could live on the peninsula for the rest of their lives.

Reaching Kalawao County requires either a small airplane or a steep descent down the pali trail from the rest of Molokai. The trail has been effectively closed to the general public since a 2018 landslide destroyed a bridge on the second switchback, though residents and workers still use it. Kalaupapa Airport has scheduled service to Molokai Airport and Honolulu. For the general public, permits to enter Kalawao County can only be obtained by purchasing a tour from an authorized operator, and visitors must be at least 16 years old. Freight arrives once a year by barge. There are no restaurants, no hotels, no gas stations. The county's isolation was designed as a prison. What it became, over time, was something closer to a sanctuary: a place where people who had been cast out by their own society rebuilt their lives, and where the few who remain have chosen to stay.