Gamelan () (Javanese: ꦒꦩꦼꦭꦤ꧀, Sundanese: ᮌᮙᮨᮜᮔ᮪, Balinese: ᬕᬫᭂᬮᬦ᭄) is the traditional ensemble music of the Javanese, Sundanese, and Balinese peoples of Indonesia, made up predominantly of percussive instruments. The most common instruments used are metallophones played by mallets and a set of hand-played drums called kendhang/Kendang, which register the beat. The kemanak (a banana-shaped idiophone) and gangsa (another metallophone) are commonly used gamelan instruments in Bali. Other instruments include xylophones, bamboo flutes, a bowed instrument called a rebab, a zither-like instrument siter (in Javanese ensemble) and vocalists named sindhen (female) or gerong (male).

Although the popularity of gamelan has declined since the introduction of pop music, gamelan is still commonly played in many traditional ceremonies and other modern activities in Indonesia, both at formal and informal events. Gamelan is played to accompany religious rituals, ceremonies, dance, dance-drama, traditional theater, wayang puppets theatre, singing, concerts, festivals, exhibitions, and many more. Many consider gamelan to be an integral part of Indonesian culture.

In 2014, Gamelan traditions were recognized as part of the National Intangible Cultural Heritage of Indonesia by the Indonesian Ministry of Education and Culture.

On December 15, 2021, Gamelan was inscribed onto the UNESCO Representative List of the Intangible Cultural Heritage of Humanity. The nomination builds on the archaeological connection to the Borobudur, and includes a focus on its role in fostering a sense of national identity and pride, in addition to wellbeing aspects such as mental health, the development of interpersonal skills and the connection between its cosmology and an ethics of mutual respect and care. The listing consists of Javanese gamelan (gamelan jawa) of Central Java and Special Region of Yogyakarta, Balinese gamelan (gamelan bali) of Bali, Sundanese gamelan (gamelan sunda) of West Java, Madurese gamelan (gamelan madura) and Banyuwangian Gamelan (gamelan banyuwangi) of East Java, Gendang beleq of West Nusa Tenggara, Banjarese gamelan (gamelan banjar) of South Kalimantan, Gamelan peking of Lampung, and Talempong of West Sumatra as a Masterpiece of Oral and Intangible Heritage of Humanity from Indonesia, and encouraged the Indonesian people and the Indonesian government to safeguard, transmit, promote, and develop the gamelan. Methods include the support of national, international and provincial festivals, the establishment of educational curricula including the Gamelan Goes to School program, an intention to increase the numbers of regional gamelan associations, and cultural diplomacy by sending gamelan specialists to global universities.