He graduated in 1937 with a Bachelor in Spanish and Russian, but chose to stay on at the university as an assistant librarian, beginning a Doctor of Philosophy on the history of Russian printing.
He joined the library at Birmingham University as a "library boy" in 1932, and in 1934 began to study Russian under Professor Konovalov. This was interrupted by the outbreak of World World War World War II
After service in World World War II and three more years at Birmingham University, Simmons moved to Oxford after an invitation to take up a job as librarian/lecturer in charge of Slavonic books at Oxford University. This position was created for him by his old tutor Konovalov.
Due to his actions in August 1953, when he travelled to Moscow to propose to the director of the Lenin Library a book exchange, the University received thousands of valuable, out-of-print Russian publications.
Simmons was instrumental in building up the retrospective collections of Russian books in the Taylorian and Bodleian Libraries and the creation in the Bodleian of the only specialised Slavonic reading room in the country. John Simmons remained an important figure in the field of Slavonics right to his death in September 2005.
His Sandars lectures, given in Cambridge in 1974 are still the only serious English-language history of Russian printing. In 1985 he formed an institution named The 4Cs Club.
The "4 Cs" stood for his four "categoricals": Conserve, Consider, Contribute, Company-operate.
The members of the club (who now number over 200 in 19 countries) were given club ties (brooches for women were introduced at a later date) and encouraged to wear them on important occasions.