The Sasak people (Sasak: Dengan Sasaq, Sasak script: ᬲᬸᬓᬸ​ᬲᬲᬓ᭄; Indonesian: Orang Sasak) or Sasaknese mainly lives on the island of Lombok, province of West Nusa Tenggara, Indonesia, numbering around 3.6 million (85% of Lombok's population). They are related to the Balinese in language and in ancestry and other ethnic groups on neighboring island Sumbawa. The indigenous people of Lombok which is the oldest community on the island are called Bayan.

Sasak people are predominanty muslim, Sasak people who practice pre-Islamic beliefs are also known as Sasak Boda in reference to the name of the Sasak people's original religion, Bodha (Boda),

There is a possibility that the origin of the name Sasak came from the word sak-sak, which means "boat". In the Nagarakretagama, the word Sasak is mentioned together as one with Lombok Island, namely Lombok Sasak Mirah Adhi. According to local tradition, it is believed that the word Sasak came from sa'-saq which means "the one". Followed by the word Lombok which originates from the word Lomboq, meaning "straight". Hence by combining the words together Sa'-saq Lombok, it means "something that's straight". Other translations also includes "a straight road". Lombok Sasak Mirah Adhi is taken from the Nagarakretagama (Desawarnana) literature, a scripture written by Mpu Prapanca that records the power and rule of the Majapahit kingdom. The word Lombok in Kawi means "straight" or "honest", Mirah means "gem", Sasak means "statement", and Adhi means "something that's good" or "utmost". Therefore Lombok Sasak Mirah Adhi means "honesty is the gem that states out goodness".

Little is known about Sasak history except that Lombok was placed under direct rule of the Majapahit prime Minister, patih Gajah Mada. Islam arrived into the area around the 15th century. The Sasaks converted to Islam between the late 16th century to early 17th century under the influence of Pangeran Prapen (Sunan Prapen), the son of Raden Paku (Sunan Giri) or Sunan Giri himself and the Muslim Makassarese, frequently mixing basic Islamic beliefs with Hindu-Buddhist beliefs, thus creating the Wetu Telu religion. Lombok was conquered by the Gelgel Balinese kingdom in the early 16th century, thus bringing a large population of Balinese to Lombok. The Balinese population of Lombok today is about 300,000, 10–15% of Lombok's population. The Balinese have also strongly influenced the Wetu Telu religion of Lombok.

The Sasak language is an Austronesian language that belongs to the Malayo-Sumbawan branch, mostly found in western Indonesia and Malaysia. Specifically, Sasak belongs to the languages of Western Indonesia which also means it is closely related to the languages of Java and Bali. There are also a number of Sasak dialects in various regions such as Kuto-Kute (North Sasak), Meno-Mene (Central Sasak), Meriak-Meriku (Central South Sasak), Ngeno-Ngene (Central East Sasak, Central West Sasak), Ngeto-Ngete (Northeast Sasak) and so on.

Most of the Sasaks today are adherents of the Lima Waktu version of Islam. Lima Waktu or Five Times signifies the five daily prayers which Muslims are required to do.

The term Lima Waktu is used to distinguish them from the Sasaks who are practitioners of Wetu Telu or Three Symbols who only pray three times a day. Orthodox Islamic teachers generally instruct adherents to pray five times a day.

Large numbers of people adhering to the Wetu Telu branch can be still found throughout the island, especially in the village of Bayan, where the religion originated. Large Wetu Telu communities can be still found in Mataram, Pujung, Sengkol, Rambitan, Sade, Tetebatu, Bumbung, Sembalun, Senaru, Loyok and Pasugulan.^{[citation needed]}