A massive power blackout hits the Indonesian island of Java; affecting almost 100 million people, it is one of the largest and most widespread power outages in history.

The 2005 Java–Bali Blackout was a power outage across Java and Bali on 18 August 2005, affecting some 100 million people.

Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian and Pacific oceans. Comprising over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea, Indonesia is the world's largest archipelagic state and the 14th-largest country by area, at 1,904,569 square kilometres. With over 280 million people, Indonesia is the world's fourth-most-populous country and the most populous Muslim-majority country. Java, the world's most populous island, is home to more than half of the country's population.

Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 156.9 million people in mid 2024, projected to rise to 158 million at mid 2025, Java is the world's most populous island, home to approximately 56% of the Indonesian population while constituting only 7% of its land area. Indonesia's capital city, Jakarta, is on Java's northwestern coast.

This is a list of notable wide-scale power outages. To be included, the power outage must conform to all of the following criteria:

• The outage must not be planned by the service provider.
• The outage must affect at least 1,000 people.
• The outage must last at least one hour.
• There must be at least 1,000,000 person-hours of disruption.