The library holds personal papers and letters of notable figures, among them the novelist Elizabeth Gaskell and the scientist John Dalton.

The architectural style is primarily neo-Gothic with elements of the Arts and Crafts movement in the ornate and imposing gatehouse, facing Deansgate, which dominates the surrounding streetscape.

[10] Enriqueta Rylands purchased a site on Deansgate for her memorial library in 1889 and commissioned a design from architect Basil Champneys.

[5][11] Mrs Rylands commissioned the Manchester academic Alice Cooke to index the vast library of the 2nd Earl Spencer which she had purchased and another collection of autographs.

Thereafter frequent disagreements arose and Mrs Rylands selected decorative elements, window glass and statues against his wishes.

[13] Another notable purchase made by Mrs Rylands was that of over 6,000 manuscripts from the Bibliotheca Lindesiana of James Lindsay, 26th Earl of Crawford at Haigh Hall in 1901.

[18] After its inauguration on 6 October 1899 (the wedding anniversary of John Rylands and Enriqueta Tennant),[13] the library opened to readers and visitors on 1 January 1900.

Champneys designed a pitched roof but Mrs Rylands was advised that an internal stone vault would reduce the fire risk and it was not built.

The site chosen by Mrs Rylands was in a central and fashionable part of the city, but was awkward in shape and orientation and surrounded by tall warehouses, derelict cottages and narrow streets.

[25] The position was criticised for its lack of surrounding space and the fact that the valuable manuscript collections were to be housed in "that dirty, uncomfortable city ... [with] not enough light to read by, and the books they already have are wretchedly kept" (written in 1901 about the Crawford MSS.

[25] Champneys incorporated this suggestion into his design, setting the two towers of the façade twelve feet back from the boundary and keeping the entrance block low, to allow light into the library.

[29] The red 'Barbary plain' sandstone, which Champneys believed 'had every chance of proving durable' for the exterior, was an unusual choice in late Victorian Manchester.

It proved relatively successful, as an inspection by Champneys in 1900 revealed little softening by the 'effects of an atmosphere somewhat charged with chemicals' although, by 1909 some repairs were needed.

The ornate Deansgate façade has an embattled parapet with open-work arcading under which is a central three-bay entrance resembling a monastery gatehouse.

[31] On either side of the entrance portal are square two-storey two-bay wings with plain walls with a string course containing grotesques and large octagonal lanterns.

[26] Embellishments in the reading room include two large stained glass windows with portraits of religious and secular figures, designed by C. E. Kempe; a series of statues in the reading room by Robert Bridgeman and Sons of Lichfield;[32] and bronze work in the art nouveau style by Singer of Frome.

This took some years to achieve due to the inexperience of contractors,[15] but the library became one of the first public buildings in Manchester to be lit by electricity[5][35] and continued to generate its own supply until 1950.

[36] The ground floor was built with numerous air inlets and, although his client felt it would prove impossible to exclude foul air, Champneys installed jute or hessian screens to trap the soot, with water sprays to catch the sulphur and other chemicals,[36] which was a very advanced system for the period.

[36] By 1900 the ventilation system had evolved to include electric fans to draw in air at pavement level through coke screens sprayed with water.

[54] In addition to the collections of Spencer, Crawford, Christie and Bullock,[55][56] holdings have been enriched by gifts, permanent loans or purchases of several libraries belonging to institutions and individuals.

These include the French Revolution Broadsides donated by the 27th Earl of Crawford in 1924[57][58] and the archives of the Methodist Church of Great Britain in 1977.

The British Pop Archive, a national collection dedicated to the preservation and research of popular culture, opened with an exhibition at the library in May 2022.

It was relaunched in 2013, with Professor Peter Pormann as director, as a collaboration between The University of Manchester's Faculty of Humanities and The John Rylands Library.

In addition, generous philanthropic donations from Amin Amiri, David Shreeve, The Soudavar Memorial Foundation and Mark Younger, amongst others, have helped to support a range of important projects.

[81] Mrs. Rylands established a board of trustees to hold the library's assets and a council of governors to maintain the building and control expenditure.