[6] It is part of a religious commandment given by Guru Gobind Singh in 1699, founding the Khalsa order and introducing the five articles of faith (the five Ks) which must be worn at all times.

It is derived from or related to Sanskrit कृपाण (kṛpāṇa, “sword, dagger, sacrificial knife”), ultimately from the Proto-Indo-European stem *kerp-, from *(s)ker, meaning "to cut".

Sikhs are expected to embody the qualities of a Sant Sipahi or "saint-soldier", showing no fear on the battlefield and treating defeated enemies humanely.

[10] They vary in size and a Sikh who has undergone the Amrit Sanskar ceremony of initiation may carry more than one; the Kirpans must be made of steel or iron.

The tenth and final guru, Guru Gobind Singh formally included the kirpan as a mandatory article of faith for all baptised Sikhs,[16] making it a duty for Sikhs to be able to defend the needy, suppressed ones, to defend righteousness and the freedom of expression.

Other issues not strictly of legality arise, such as whether to allow carrying of kirpans on commercial aircraft or into areas where security is enforced.

[17] After members of Sydney's Sikh community spoke out and defended their children's rights to bring religious items to school,[18] the state's Department of Education reversed this decision in August 2021 and implemented new guidelines around the bringing of kirpans with the following conditions:[19] In August 2023, the state of Queensland repealed a previous ban on bringing knives to schools and other public places after Australian Sikh Kamaljit Kaur Athwal took the Queensland state government to court in 2022.

[21] In most public places in Canada a kirpan is allowed, although there have been some court cases regarding carrying on school premises.

[24] On 9 February 2011, the National Assembly of Quebec unanimously voted to ban kirpans from the provincial parliament buildings.

[26] As of 27 November 2017, Transport Canada has updated its Prohibited Items list to allow Sikhs to wear kirpans smaller than 6 cm (2.4 in) in length on all domestic and international flights (except to the United States).

Ripudaman Singh, who now works as a scientist, was earlier convicted by the City Court of breaking the law by publicly carrying a knife.

Danish law allows carrying of knives (longer than 6 centimeters and non-foldable) in public places if it is for any purpose recognized as valid, including work-related, recreation, etc.

[35][36] As a bladed article, possession of a kirpan without valid reason in a public place would be illegal under section 139 of the Criminal Justice Act 1988.

[37] There is an identical defence to the similar offence (section 139A) which relates to carrying bladed articles on school grounds.

"[41] In New York City, a compromise was reached with the Board of Education whereby the wearing of the knives was allowed so long as they were secured within the sheaths with adhesives and made impossible to draw.

The tightening of air travel security in the 21st century has caused problems for Sikhs carrying kirpans at airports and other checkpoints.