His earliest school records state that he was born on October 20, 1875. However, Jinnah's first biography, authored by Sarojini Naidu, as well as his official passport state the date of birth as December 25, 1876.Jinnah was the first child born to Mithibai and Jinnahbhai Poonja. His father, Jinnahbhai (1857"“1902), was a prosperous Gujarati merchant who came from the Paneli Moti a village in the state of Gondal situated in the Kathiawar region province of Gujarat (present day India). He had moved to Karachi from Kathiawar, because of his business partnership with Grams Trading Company whose regional office was set up in Karachi, then a part of the Bombay presidency. He moved to Karachi some time before Jinnah's birth.The first-born Jinnah was soon joined by six siblings: three brothers"”Ahmad Ali, Bunde Ali, and Rahmat Ali"”and three sisters: Maryam, Fatima and Shireen. Their mother tongue was Gujarati; in time they also came to speak Kutchi, Sindhi and English.[21] The proper Muslim names of Mr. Jinnah and his siblings, unlike those of his father and grandfather, are the consequence of the family's migration to the predominantly Muslim state of Sindh.

Jinnah was a restless student and studied at several schools: first at the Sindh-Madrasa-tul-Islam in Karachi; then briefly at the Gokal Das Tej Primary School in Bombay; and finally at the Christian Missionary Society High School in Karachi,[14] where, at the age of 16, he passed the matriculation examination of the University of Bombay.[22]During his student years in England, Jinnah came under the spell of 19th-century British liberalism, like many other future Indian independence leaders. This education included exposure to the idea of the democratic nation and progressive politics.

In the 1946 elections for the Constituent Assembly of India, the Congress won most of the elected seats, while the League won a large majority of Muslim electorate seats. The 1946 British Cabinet Mission to India released a plan on May 16, calling for a united Indian state comprising considerably autonomous provinces, and called for "groups" of provinces formed on the basis of religion. A second plan released on June 16, called for the separation of India along religious lines, with princely states to choose between accession to the dominion of their choice or independence. The Congress, fearing India's fragmentation, criticised the May 16 proposal and rejected the June 16 plan. Jinnah gave the League's assent to both plans, knowing that power would go only to the party that had supported a plan. After much debate and against Gandhi's advice that both plans were divisive, the Congress accepted the May 16 plan while condemning the grouping principle.[citation needed] Jinnah decried this acceptance as "dishonesty", accused the British negotiators of "treachery",[45] and withdrew the League's approval of both plans. The League boycotted the assembly, leaving the Congress in charge of the government but denying it legitimacy in the eyes of many Muslims.Jinnah had initially avoided joining the All India Muslim League, founded in 1906, regarding it as too Muslim oriented. However, he decided to provide leadership to the Muslim minority. Eventually, he joined the League in 1913 and became the president at the 1916 session in Lucknow. Jinnah was the architect of the 1916 Lucknow Pact between the Congress and the League, bringing them together on most issues regarding self-government and presenting a united front to the British. In 1906, Jinnah joined the Indian National Congress, which was the largest Indian political organization.