The Library of Institute of Baltic Region History and Archaeology contains the following collections:
- Book collection of historian, Prof Leonas Mulevičius (1927–1993)
- Book collection of numatist Stasys Janušonis (1937–1983) (acquisition funded by Klaipėda University)
- Book collection of historian, Dr Rimantas Jasas (1929–2002) (acquisition funded by the Open Society Fund Lithuania)
- Book collection of archaeologist Prof Dr habil. Vytautas Kazakevičius (1951–2005) (donated by widow Danutė Kazakevičienė in 2006)
- Book collection of the former Lithuanian embassy in Paris (handed over to the library of BRIAI by the Ministry of Foreign Affairs of the Republic of Lithuania in 2010)
- Archive and printed collection of Chicago Lithuanian Evangelical Lutheran Parish Tėviškė (handed over to the BRIAI in 2011).
- Book and manuscript collection of American Lithuanian historian, Dr Algirdas Martynas Budreckis (1937–2000) (donated by his widow in 2013)