Born in 1872 in a Sikh family of Village Chainwali, Sialkot, Buta Singh embraced Islam in 1887 and adopted the name Ubaidullah. Leaving his home he went to Barchandi, Sindh, where he became a disciple of a Sufi, Hafiz Mohammad Siddiq, and adopted the suffix Sindhi to his name.
After learning elementary Arabic in Bahawalpur, he reached Deoband where he studied at the Darul -Uloom from 1889 to 1905, and came into the influence of Sheikh -ul-Hind Maulana Mahmudul Hasan.
On graduation, he served as a teacher in Sindh, in 1908 he was recalled by the Sheikh-ul-Hind and was entrusted with the task of organizing Jamait-ul-Ansar, in 1913 due to differences with Darul-Uloom administration over his political ideas and activities, he was deputed to Nizarat-ul-Maarif at Delhi. Perhaps he was dismissed from the Darul-Uloom. In Delhi he gave discourses on the Holy Quran to the English -educated youth and trained them for revolutionary activity.
Inspired by Sheikh Ismali Shahid, in 1915, he became very actively involved in the Freedom Movement. He was a leading figure in the Silk Handkerchief Conspiracy whose object was to promote an Afghan attack on India which would synchronize with Muslim rebellion within the country against the British rule. The British caught sent of the conspiracy and he was forced to leave India. Passing through the Mujahirin colony in the tribal area of North West Frontier, he reached Kabul and joined Indian revolutionaries there. They established contacts with the Turkish and German missionaries in Kabul. When Raja Mahendra Pratap and Moulvi Barkatullah set up the first Provisional Government of Free Indian in Kabul as President and Prime Minister respectively, Ubaidullah was named one of the Ministers. While in Kabul, he organized a branch of the Indian National Congress. He then planned to form an ‘ Army of God’ with headquarters in the holy city of Madina in Arabia, of which Sheikhul- Hind was to be the General-in-Cheif.
After the Third Afghan War and the restoration of peace between British and the Afghan Government, he was expelled from Afghanistan. He went to the USSR and reached Moscow in December 1992. He was very much inspired by the impact of the Russian Revolution. He also visited Turkey and studied the Kemalist reforms, he lived in exile until 1939, when through the intervention of Premier Allah Baksh of Sindh, he was permitted by the British Government to return to India.
No longer a firebrand, Ubaidullah Sindhi formed the Ganga-Jamuna Sindh party. He died on 21st August 1944.
Ubaidullah was an orthodox Muslim, yet he stood for modernity and tried to reconcile nationalism and with Islam. Ideologically he belonged to the school of Shah Waliullah. His basic thesis was that though India was not a nation but composed of many nationalities, their partnership was essential in the struggle for freedom and governing free India. Thus he stood for Hindu-Muslim unity.
He remained a Congressman all his life but critical of Mahatma Gandhi’s leadership, he slowly moved out of the mainstream and ceased to be a political force.
A prolific writer. his autobiography was published posthumously in 1947 under the title Zaati diary. Safarnama-e-Kabul, Shah Waliullah or unki Siyasi Tahrik (1942), Shah Waliullah aur unka Siyasi Falsafa ( 1944) and Khutbat – i-Ubaidullah Sindhi ( 1942).