Cognitive reappraisal and expressive suppression have long been considered the two most important emotion regulation strategies. Increasingly, studies have found that mindfulness has a relationship with them. However, the magnitude and direction of the relationship between them have yet to reach a consistent conclusion. To this end, a three-level meta-analysis was used to explore the relationship between mindfulness, cognitive reappraisal, and expressive suppression. Thirty-six studies were included in the meta-analysis through a literature search, including 36 samples with 83 effect sizes and a total of 12,026 subjects. The three-level random effects model showed that mindfulness was positively correlated with cognitive reappraisal to a low to moderate degree but was not correlated with expressive suppression. The moderating effect analysis showed that the relationship between mindfulness and cognitive reappraisal was slightly closer in males than in females. The study found a relatively stable positive relationship between mindfulness and cognitive reappraisal, an adaptive emotion regulation mode, while the relationship with expressive suppression was insignificant. The finding supported the affect regulation training model and also shed light on potential areas for future studies.