Roger Marsh Blench (born August 1, 1953) is a British linguist, ethnomusicologist and development anthropologist. He has an M.A. and a Ph.D. from the University of Cambridge and is based in Cambridge, England.^{[self-published source?]} He researches, publishes, and works as a consultant.

Blench is known for his wide-ranging interests and has made important contributions to African linguistics, Southeast Asian linguistics, anthropology, ethnomusicology, ethnobotany, and various other related fields. He has done significant research on the Niger–Congo, Nilo-Saharan, and Afroasiatic families, as well as the Arunachal languages. Additionally, Blench has published extensively on the relationship between linguistics and archaeology. Blench is currently engaged in a long-term project to document the languages of central Nigeria. He has also expressed concern about ranching in Nigeria.

Blench collaborated with the late Professor Kay Williamson, who died in January 2005, and is now a trustee of the Kay Williamson Educational Foundation, which exists both to publish the unpublished material left by Kay Williamson and to promote the study of Nigerian languages. A series of publications supported by the trust is under way with Rüdiger Köppe Verlag in Cologne.

Blench has also conducted research and evaluations of international development activities worldwide, as a consultant and research fellow of the Overseas Development Institute in London.

Old North African speakers, who have been misidentified as Paleoberbers and did not speak a language(s) that is linguistically related to existing Berber languages, were foragers of prehistoric North Africa that spoke a presently extinct set(s) of languages. Roger Blench coined the term, "Old North African," to describe and distinguish earlier languages spoken in North Africa from later languages spoken by incoming Berber speakers, Punic speakers, and Arabic speakers.

From coastal North Africa to Iberia (e.g., Spain), ethnic groups spoke a set(s) of languages known as Old North African, which were not necessarily genetically related to one another. Ethnic groups of Iberia that spoke the Tartessian language may be considered Old North African speakers. Ethnic groups and the archaeological cultures of North Africa that came before the Capsian culture, ethnic groups of the Capsian culture, and ethnic groups of the Neolithic Maghreb are considered to be Old North African speakers. As large animals migrated into and across the Green Sahara, Old North African speakers, who hunted them as game animals, also migrated into and across the Sahara. The variety of cultures in the Maghreb described by Herodotus in 2500 BP may have been the cultural variety existing among Old North African speakers at that time.

In 300 BCE, Guanche speakers, who may have been Old North African speakers rather than Berber speakers, may have peopled the Canary Islands. Though speculative, Guanche speakers may have spoken the Basque language, Tartessian language, and other similar languages of the Iberian Peninsula; supportive evidence for this view may be found in the few lexemes that have been related to the Basque language and an absence of Berber etymology found in some Guanche words.

Due to the migration of incoming Arabic (e.g., Hassānīya), Berber (e.g., Tuareg), and Punic speakers, Old North African languages may have eventually ceased being spoken in North Africa.