Social networking sites are widespread worldwide, and Facebook is the leading platform in terms of the number of users, laying the ground for potential problematic use. However, problematic Facebook use does not occur for most users but only for a minority. Previous research has found an association between the Big-five personality traits and problematic Facebook use, but the direction of these associations remains controversial. We aimed to fill this gap in knowledge through a systematic review and meta-analysis comprising 425 effect-sizes (78 studies) and 39,930 individuals (females = 33 % to 89 %; age range = 17 to 48 years). Extraversion and neuroticism were associated with higher daily and weekly hours spent on Facebook, while conscientiousness was negatively associated with higher daily hours and not weekly hours. However, when time spent on Facebook was assessed by validated questionnaires, different patterns of associations were observed. Except for the non-significant role of extraversion, the other personality traits were negatively associated with problematic Facebook use, while neuroticism was positively associated. When using different assessment tools was considered, extraversion remained non-significant, but different association patterns were observed. Moreover, for compensatory Facebook use, all personality traits were negatively associated with it, whereas neuroticism exhibited a positive association. Different patterns of associations in terms of strength and direction were observed depending on samples and measures characteristics; thus, definitive conclusions on the direction of the associations are impossible to draw at present. A more robust conceptualization and assessment of problematic Facebook use, as well as time spent on it, is required. Implications, limitations, and future directions are discussed.