The present research paper titled, “Centennial Libraries in Mumbai: with special reference to Sarvajanik Vachanalay (Public Library), Kalyan, intends to study how it helped in social change and development in the ancient port city Kalyan. Sarvajanik Vachanalay (Public Library) Kalyan was established on 3rd February, 1864, with the efforts of Rao.i Sadashiv Moreshwar Sathe. Rao. Sadashiv Sathe initially established this Vachanalay (Library), at his own place and named it as ‘Native Vachanalay (library).’ In 1884, it was shifted to Dak (Lat Veredus, Veredius)ii Bungalow building and was renamed as ‘General Library’. Later inspired by Lokmanya Tilak (The great leader of Indian National Congress who followed Extremist ideology, one of the tripartite commonly known as Bal amongst the Lal, Bal, and Pal), it got its todays name i.e., ‘Sarvajanik Vachanalay Kalyan.’ The occasion was blessed by a great author of Marathi Literature N. C. Kelkar, who is fondly known as ‘Tatyasaheb Kelkar.’ Initially Sarvajanik Vachanalay Kalyan was the center, responsible in the social, economic, and political development in Kalyan. Located at the nodal center of the city, along with its technical growth as a library it has also proved as a center for new thoughts towards the independence of India. It has been a prominent place for the research scholars, for authors and writers, for those who wanted to inculcate the development the thoughts of Renaissance in the Kalyan city and Bombay (Mumbai) in general. As we see Bombay has witnessed many new beginnings of culture and thinking, similarly Sarvajanik Vachanalay Kalyan has been the center for the same. Our former President of India, Hon’ble APJ Abdul Kalam wanted India to always get acquainted with modern technology and implement the same. Therefore, the Sarvajanik Vachanalay Kalyan 1 introduced the system of e-book in the Vachanalay. The book titled ‘Subhe Kalyan,’ authored by Dr. Vivekanand Godbole was the first such book which was converted into e-book.