Sewapanthi (Punjabi: ਸੇਵਾਪੰਥੀ; meaning "fellowship of service"), alternatively spelt as Sevapanthi, and also known as Addanshahi, is a traditional Sikh sect or order (samparda) that was started by Bhai Kanhaiya, a personal follower of the ninth Sikh Guru, Guru Tegh Bahadur. Kanhaiya was instructed by the Guru to go out and serve humanity, which he did by establishing a dharmasala in the Attock district of Punjab and serving indiscriminately. Sewa Panthis are also known as 'Addan Shahis'. This name is derived from one of Bhai Kanhaiya's disciples, Addan Shah.

Guru Tegh Bahadur had a follower known as Kanhaiya Lal, a Dhamman (Dhiman) Khatri who was born in 1648, in a town called Sohadara, now in Pakistan. He became a drawer of water to the Guru's horses. The Guru gave Kanhaiya a seli topi as a reward.

Once the 10th Guru, Guru Gobind Singh, had ascended to the gurgaddi, Bhai Kanhaiya began to follow him. Allegedly, Guru exempted Kanhaiya and his followers from military duty and told him to carry on performing the duty allotted to him by his reverend, Guru Tegh Bahadur, of serving all living beings.

In the Battle of Anandpur, Bhai Kanhaiya served water indiscriminately to wounded soldiers in the battlefield, including the opposition (Mughals). For this act, angry Sikh warriors accused him of treason brought him before the Guru. When he asked him why he was helping the wounded enemy, Kanhaiya replied that he could not distinguish between friend or foe, as he only saw Waheguru in all. The Guru was very pleased, and not only did he order Kanhaiya to continue, but also gave him a medicine chest as a gift. He then blessed him, saying after him shall be a Sikh order.

The langar hall at the Golden Temple's construction was supervised by Sewapanthi saints. A prominent Sewapanthi scholar in the 20th century was Sant Pandit Nischal Singh, who died in 1978.

Traditionally Sehajdhari Sikhs, nowadays many Sewapanthis are becoming Khalsa Sikhs. The Sewapanthis are extremely small in number and barely exist today.

The main focus of the sect is on the selfless service to others, hence their name. The Sewapanthi Sikhs usually wear pure white clothes, and keep kesh (unshorn hair). They have often had their deras and dharamsalas located in places like Punjab, Pakistan, and other with Muslim majority populations. Many of the followers of the sect were ethnic Sindhi Sikhs. Due to this, engagements with Sufi texts and Islamic literature has been common among the Sewapanthis historically. The Sewa Panthis are pacifists. Though they do not say it is wrong for a person to defend themselves, Sewapanthis themselves desist from all forms of violence. As such, many Sewapanthis foregoe the pahul, or initiation into the martial Khalsa order.

The Sewapanthi dress is white, and they refuse to harm other forms of life in an aspiration to become the epitome of shaant ras, and to remain in sattva guna. Despite this, they do not entirely detach themselves from the martial spirit expounded upon by Guru Gobind Singh. They support, in principle, the necessary violent actions required of the Khalsa for the protection of Dharma.