Sikhs ( or ; Punjabi: ਸਿੱਖ, sikkh [sɪkkʰ] Devanagari: सिख) are people who adhere to Sikhi or Sikhism, an Indian religion that originated in the late 15th century in the Punjab region of the Indian subcontinent, based on the revelation of Guru Nanak. The term Sikh has its origin in the Sanskrit word śiṣya (शिष्य), meaning 'disciple' or 'student'.

Male Sikhs generally have Singh ('lion') as their last name, though not all Singhs are necessarily Sikhs; likewise, female Sikhs have Kaur ('princess') as their last name. These unique last names were given by the Gurus to allow Sikhs to stand out and also as an act of defiance to India's caste system, which the Gurus were always against. Sikhs strongly believe in the idea of sarbat da bhala (welfare of all) and are often seen on the frontline to provide humanitarian aid across the world.

Sikhs who have undergone the Amrit Sanchar ('baptism by Khanda'), an initiation ceremony, are from the day of their initiation known as Khalsa, and they must at all times have on their bodies five Ks:

1. kesh, uncut hair usually kept covered by a dastār, also known as a turban;
2. kara, an iron or steel bracelet;
3. kirpan, a dagger-like sword tucked into a gatra strap or a kamar kasa waistband;
4. kachera, a cotton undergarment; and
5. kanga, a small wooden comb.

The Punjab region of the Indian subcontinent has been the historic homeland of the Sikhs, having even been ruled by the Sikhs for significant parts of the 18th and 19th centuries. Today, Canada has the largest national Sikh proportion (2.1%) in the world, while Punjab state in India has the largest Sikh proportion (58%) amongst all administrative divisions in the world. Many countries, such as Canada and the United Kingdom, recognize Sikhs as a designated religion on their censuses, and, as of 2020, Sikhs are considered as a separate ethnic group in the United States. The UK also considers Sikhs to be an ethno-religious people, as a direct result of the Mandla v Dowell-Lee case in 1982.