Akali Phula Singh Nihang (born Phula Singh; 14 January 1761 – 14 March 1823) was an Akali Nihang Sikh leader. He was a saint soldier of the Khalsa Shaheedan Misl and head of the Budha Dal in the early 19th century. He was also a senior general in the Sikh Khalsa Army and commander of the irregular Nihang of the army. He played a role in uniting Sikh misls in Amritsar. He was not afraid of the British who at many times ordered for his arrest but were not successful. During his later years he served the Sikh Empire as a direct adviser to Maharaja Ranjit Singh. He remained an army general in many famous Sikh battles up until his martyrdom in the battle of Nowshera. He was admired by the local people and had a great influence over the land and his settlement was always open to help the poor and helpless. He was well known and was a humble unique leader and prestigious warrior with high character. He was also known for his effort to maintain the values of Gurmat and the Khalsa panth.

Akali Phula Singh was born in 1761 in a Jat family, to father Sardar Ishar Singh. After his father's death Akali Phula Singh, who was still young, and his elder brother, Baba Sant Singh, were taken care of by Mahant Balram and under his mother's advice he would later be taken under the apprenticeship of Akali Baba Naina Singh, the leader of the Shaheedan Misl, and his Nihang order at Anandpur Sahib. It was from Baba Naina Singh that he would receive initiation into the Khalsa.

Akali Phula Singh memorized the Nitnem (The writings of the Sikh Gurus which are recited daily by a Sikh) at a young age. As a child he would not eat until he completed memorizing a certain portion of the Sikh Guru's writings and in this way he had the Akal Ustat, 33 Savaiye, and other Sri Mukhwak Bani memorized. Around the age of fourteen Akali Phula Singh's mother also passes away after falling off stairs leaving him with the dying wishes of being virtuous, upholding dharma, helping the poor, serving the Panth, in the heart being at the refuge of the Guru, being unaffected by Moh, being a role model on the battlefield, and following the footsteps of his ancestors. This had a great impact on Akali Phula Singh who then gave away his land and his possessions to the poor to start to live the life of a Nihang Saint Soldier. He became very close to Akali Naina Singh's jatha at Anandpur Sahib where he completed his martial arts training and fought many battles. As he began to recite Gurbani with a near perfect pronunciation and began to display great dharmic strength he was made the jathedar of the Shaheedan Misl. He did considerable Seva at Anandpur Sahib which included protecting the Gurdwara from thieves and preparation of langar until eventually the Gurdwara was reformed.

Upon hearing of news of lack of maintenance and other neglect by sevadars of the Gurdwaras in Amritsar Akali Phula Singh came to Amritsar in 1800 at this time he had under his leadership a band of about 2,000 Nihangs. He stopped the mismanagement and actively began reforming many Gurdwaras within Amritsar to the point he became responsible and accepted as being in charge of the maintenance of all Gurdwaras in the area. He did Kar Seva at the holy sorawar at Harmindar Sahib and overall cleaning of the complex with the help of about 100,000 pilgrims this lasted for about 2 months. Later in his life he made similar improvements to Sri Muktsar Sahib, Anandpur Sahib, and Damdama Sahib. Seeing Akali Phula Singh's high character and dedication, the Sangat made him the Jathedar of the Akal Takht which was initiated by the Panj Pyare.

At the beginning of the nineteenth century Amritsar was ruled by the Bhangi Misl under Mai Sukhan and other Sikhs Sardars. Ranjit Singh of the Sukerchakia Misl had recently acquired the capital of Punjab, Lahore. When he approached Amritsar wanting to add it to his empire it created a problem for the ruling families of the city. In 1801 Maharaja Ranjeet Singh brought his army and the Bhangi Misl fortified Amritsar preparing for battle. There was a brief shelling where Ranjit Singh fired empty rounds into the sky in the respect of the holy city. Akali Phula Singh saw this and was saddened by the event and right when the battle was imminent he intervened between the two Sikh forces in the middle of the battlefield. He said that it was a sin for a Sikh to kill another Sikh and it was also a sin to fire cannons in Amritsar and succeeded in persuading them to stop fighting. The two parties made peace under Akali Phula Singh's advice. Ranjit Singh asked Akali Phula Singh to join his forces and he agreed, Akali Phula Singh with him added about 2,000 to 3,000 Nihangs to join the government army. Many of Ranjit Singh's future victories would be due to Akali Phula Singh and his army.

Kasur falls in fairly close proximity to Lahore and there were many Pathan-Sikh wars fought earlier between the two neighbouring empires. Previously Emperor Nizamuddin Khan agreed after battle to subdue to the Sikh empire. Nizamuddin however then broke his vow and was defeated again with Ranjit Singh forgiving him once again allowing Nizamuddin to control Kasur again. The next Nawab of Kasur and Nizamuddin son, Qutbuddin Khan, was mistreating the Sikhs and Hindus in his state and charging extra tax on them he eventually called a Jihad on the Sikh Kingdom. In February 1807 Qutbuddin Khan with the help of the Multan Nawab, Musafar Khan, gathered thousands of soldiers in Kasur where there was a big fort. Akali Phula Singh and his jatha were called to Lahore by Maharaja Ranjit Singh to fight in Kasur, Jodh Singh Ramgarhia and Hari Singh Nalwa were also called in. Akali Phula Singh and his soldiers led the attack on the Muslim Ghazis on the morning of 10 February 1807. Two battles were fought outside the city and the Singhs won both. Qutbuddin retreated to his fort as he had nowhere to go.

For one full month the Sikh cannons fired at the walls of the fort. The Sikh Army broke a hole through in a section of the wall by putting gunpowder underneath the fort doors. Akali Phula Singh and his Nihangs were the first to charge through the breach and after hand-to-hand fighting the Sikhs gained victory. Qutbuddin tried to run away but was soon caught. After begging for mercy Maharaja Ranjit Singh forgave him and give the Nawab a jagir of land at Mamdot, near the Sutlej River and Lahore. Kasur was made a part of Ranjit Singhs empire. After this battle Akali Phula Singh gained affection from Ranjit Singh and Akali Phula Singh became a reliable military ally. The Nihang jatha was large now and they got a jagir for Langar. At this time Akali Phula Singh and his Akalis used to ask for weapons and horses from the local leaders and if they were not given they would take them by force themselves. This stopped after Ranjit Singh gave them permission to take whatever they required from the Sikh Empire's army barracks.

The British Civil servant Charles Metcalfe met with Ranjit Singh at Kasur and then in February 1809 arrived in Amritsar to go to Ranjit Singh's court for the signing of the Treaty of Amritsar. Metcalfe was interested in the creation of the pastili^{[check spelling]} boundary and establishing an English treaty made by suffledge where boundaries will be respected between British and Sikh empires. Metcalfe came with his platoon who were composed of entirely Shia Muslims. It was the Shia Muslims commemoration of Muharram and they took it upon themselves to enact this ritual in the streets of Amritsar. The army of about 100 Muslim soldiers began beating their breasts to the chants of "Hassan, Hussein, Ali" and making much noise as they came near the Harmindar Sahib complex where Akali Phula Singh and his jatha were staying.