The impact of language learning strategy use on achievement has been extensively researched in the traditional foreign language classroom. However, little is known about this topic in the context of online learning. In addition, previous research has focused primarily on English as a foreign or second language. This study fills these gaps by investigating the use of language learning strategies by students taking a beginner-level online course in a foreign language other than English at a Swedish university. The study examined the extent to which students used language learning strategies, whether age was related to the use of language learning strategies, and whether language learning strategy use increased the likelihood of foreign language achievement, operationalised as receiving the highest final course grade. Participants (n= 108), aged 19–76 years (M = 37.6), completed the Strategy Inventory for Language Learning (Oxford, 1990). Three main findings emerged from the study. First, the students used metacognitive strategies most frequently, which could be explained by the fact that the online format requires great learner autonomy. Second, age was negatively but weakly related to the use of memory and affective strategies. Third, the use of cognitive strategies significantly increased the likelihood of foreign language achievement almost tenfold. Thus, this category of strategies appeared to be a strong predictor of achievement among the study participants.