<jats:title>Abstract</jats:title><jats:p>Collaborative problem-solving, the mutual engagement of people in a coordinated effort to solve a problem together, plays a critical role in the increasingly complex, linguistically diverse, and interconnected world. In particular, being able to communicate in the same languages provides a critical platform for facilitating problem solving among members of a multilingual team. Little research has explored whether sharing the same spoken languages would boost collaborative problem-solving over and beyond the effects of possible confounding variables such as language proficiency, personality, ethnicity, nationality, and non-verbal intelligence. This study manipulated the sharing of same languages by pairing 118 English-speaking bilingual participants either with someone who shares the same two spoken languages as themselves (English-<jats:italic>same</jats:italic> pair) or with someone who differs in one language (English-<jats:italic>different</jats:italic> pair). We explored whether such sharing of the same languages enhances collaborative problem-solving in multilingual pairs. Participants completed the Raven’s Matrices individually, as well as an insight problem-solving task (Triangle of Coins task) and a divergent thinking task (Mind-mapping) in pairs. English-same pairs performed better than English-different pairs in the insight problem-solving task but not in the divergent thinking task. English-different pairs collaborated (mean number of turns per minute) and communicated (mean number of utterances) more than English-same pairs in the divergent thinking task, although the effect of pair type on communication was fully mediated by a difference in ethnicity within pairs. More collaboration could have been needed between English-different pairs in the divergent thinking task to achieve comparable performance as English-same pairs, possibly due to the different communication processes experienced by English-different pairs. This study provides insights to the role of sharing spoken languages in enhancing collaborative problem-solving in small multilingual groups.</jats:p>