Collinder specialized in the Germanic loanwoards in Finnic and Sami. He was a highly productive author of scholarly literature, and also conducted fieldwork among the Sámi people. He is also noted as the translator of a number of works, including Beowulf, the Poetic Edda, the Kalevala, and many of the works of William Shakespeare. Under the initials Bj. C., he was the author of a large number of entries in Svensk uppslagsbok. His magnum opus, Comparative Grammar of the Uralic Languages, has remained the standard work on Uralic languages up to the present day.
Collinder was a member of a large number of scholarly organizations. This includes Member of the Royal Gustavus Adolphus Academy (1936), the Royal Society of the Humanities at Uppsala (1936), the Hungarian Academy of Sciences (1937), the Finnish Academy of Science and Letters (1941), the Royal Swedish Academy of Letters, History and Antiquities (1943), the Norwegian Academy of Science and Letters (1945), the Royal Society of Sciences in Uppsala (1951), the Finno-Ugrian Society, the Royal Danish Academy of Sciences and Letters (1951), and a Corresponding Member of the Finnish Literature Society (1941) and the Austrian Academy of Sciences (1966).