In Sikhism, the Five Ks (Punjabi: ਪੰਜ ਕਕਾਰ, Pañj Kakār, Punjabi pronunciation: [ˈpənd͡ʒ.ˈkəˌka:ɾ]) are five items that Guru Gobind Singh, in 1699, commanded Khalsa Sikhs to wear at all times. They are: kesh (ਕੇਸ਼, keś, unshorn hair and beard since the Sikh decided to keep it), kangha (ਕੰਘਾ, kãṅghā, a comb for the kesh, usually wood), kara (ਕੜਾ, kaṛā, a bracelet, usually made of iron or steel), kachhera (ਕਛੈਰਾ, kachairā, an undergarment), and kirpan (ਕਿਰਪਾਨ, kirpān, a small curved sword or knife made of iron or steel).

The Five Ks are not just symbols, but articles of faith that collectively form the external identity and the Khalsa devotee's commitment to the Sikh rehni, 'Sikh way of life'. A Sikh who has taken Amrit and keeps all five Ks is known as Khalsa ('pure') or Amritdhari Sikh ('Amrit Sanskar participant'), a Sikh who has not taken Amrit but follows the teachings of the Sri Guru Granth Sahib is called a Sahajdhari Sikh.

The kesh, also known as kesa, or uncut, long hair, is considered by Sikhs to be an indispensable part of the human body. It also emulates the appearance of Guru Gobind Singh and is one of the primary signs by which a Sikh can be clearly and quickly identified. A Sikh never cuts or trims any hair as a symbol of respect for the perfection of God's creation. The uncut long hair and the beard, in the case of men, form the main kakār for Sikhs.

The turban is a spiritual crown, which is a constant reminder to the Sikh that they are sitting on the throne of consciousness and are committed to living according to Sikh principles. Guru Gobind Singh told his Sikhs:

"Khalsa mero roop hai khaas. Khalsa mai ho karo nivaas... The Khalsa is my image. Within the Khalsa I reside." Wearing a turban declares sovereignty, dedication, self-respect, courage and piety.

A noted figure in Sikh history is Bhai Taru Singh, who was martyred when he refused to get his kesh cut.

Comb the hair twice a day, covering it with turban that is to be tied from fresh.

— Tankhanama Bhai Nand Lal Singh