Later, he servedas Dean of the Faculty of Law at Nagpur University from 1949 to 1953. In 1954,he was appointed as the Chief Justice of Madhya Pradesh High Court. Throughout the1950s, he kept visiting various Universities like Sagar University, Court Vikram University, and the Aligarh Muslim University.
In 1958, he further advanced as the Supreme Court Judge until finally becoming the Chief Justice of India in 1968. In 1970, he announced his retirement. He had gathered a lot of fame by becoming the youngest person to accomplish various positions in the legal fraternity like Advocate General, Chief Justice of a High Court and Judge of the Supreme Court.
Some of the notable judgments which can be attributed to him are Golak Nath case in which restriction on Parliament’s amending powers were recognized and Ranjit D Udeshi case where the law of obscenity was explained.
He was Pro-Chancellor of the Delhi University from 1968 to 1970, Chancellor of the Jamia Millia Islamia from 1969 to 1985,Chancellor of the Delhi and Punjab Universities between 1979 and 1984 and Chancellor of the Hyderabad University 2. from 1986 to 1990. He was the President of the Indian Law Institute from 1963 to1970, President of the International Law Association (Indian Branch) from 1968 to 1970 and of the Indian Society of International Law in 1969-70.
Justice Hidayatullah occupied the post of ‘Acting President of India from 1969 till the Mr. VV Giri was elected. When he retired as the CJI,he was elected as the Vice President of India. Again during this period, he served as the ‘Acting President’ in 1982.
No other judgeholds such a diverse and exemplary professional record as J. Hidayatullah. He was a member of Executive Council of the World Assembly of Judges, British Institute of International and Comparative Law, International Council of Former Scouts and Guides and Chief Scout of the Boy Scouts Association of India.
He was the President of Bombay Natural History Society and the Patron of Schizophrenic Research Foundation of India and Commonwealth Society of India. To his credit, he has represented India in various International Conferences held in different countries.
Apart from this, he was lover of literature. He used to write Urdu poetry. In his career as a judge, he was seen as an intellectual and humorous judge who could even laugh at his own self. He has written a number of books like "My Own Boswell" and "A Judge's Miscellany."