Over the centuries the Library has built up impressive collections of rare books by purchase, bequest, gift and through the Copyright Act. A number of the larger collections have been kept together and named, including some which were once private collections (as in the case of the Royal Library, the Acton Library and Sandars) and some which were once in institutional ownership (Ely and Peterborough Cathedrals, Bury School Library and the Royal Commonwealth Society). Information on these named collections may be found below.

| A*-Qq* | Aaa-Kkk | Acton | Adams | Adversaria | Arc | Bassingbourn | Bensly | Bradshaw | Brett-Smith | Broadsides | Broughton | Broxbourne | Buckley | Bury | Bute | Cam | Cam Papers | Catherine Cooke | CCA-CCE | Chapbooks | Dante | Darwin | De Laszlo | Dreyfus | Dutch works | Eikon Basilike | Ely | Forster | Gibb | Hanson | Harley-Mason | Heym | Hib | Hisp | Historical Printing Room | Hunter | Huntingdon | Hutt | Incunabula | Jennings portraits | Keynes | Leigh | Liberation | Madden | Marshall | McGhee | Meynell | Moh (sel) | Montaigne | Morison | Munby | Norton | Nov | Oates | Official Publications | Path | Peterborough | Posters | Pryme | Rel | Restif de la Bretonne | Rit | Ritschl | Rom | Rosenthal | Royal Commonwealth Society | Royal Library | Sandars | Sassoon | Sel | Sette of Odd Volumes | SPCK | SPR | Stars (A*-Qq*) | Syn | Toft | Venn | Verney | Waddleton | Wane | War of 1914-1919 | Webb | White | Williams |Yorke | Young | Yule