The present study examines the multilingual benefit in relation to language learning and mathematical learning. The objective is to assess whether speakers of three or more languages, depending on language profile and personal histories, show significant advantages in language learning and/or mathematical learning, and whether mother tongue literacy can be associated with their performance in Maths and English language tests. Participants are all multilinguals with knowledge of French as an L1 or as a non-native language. Three core groups were examined: (a) School multilinguals (n = 449), typically French L1 speakers with knowledge of two additional languages learned in a formal school context; (b) Multilinguals with Literacy in the home language (n = 45) and Multilinguals without Literacy in the home language (n = 113). All participants were given a Maths test, an English language test and a questionnaire. A questionnaire for parents was also used. Results suggest a positive role of mother tongue literacy in language learning as well as mathematical learning.