AbstractModulating emotional responses plays a crucial role in individuals' well‐being. Among various response modulation strategies, this study aims to examine surface acting, which refers to the behaviour modifying affective expression by either displaying emotions not genuinely felt, hiding one's true feelings, or both, in daily life. Using ecological momentary assessment with a college student sample, we examined when individuals use surface acting and how surface acting is associated with negative affect in everyday contexts. Furthermore, since response modulation has shown cultural variation, we investigated whether the patterns of surface acting use and its affective consequences differ between cultures (Easterners vs. Westerners). By conducting multilevel modelling, we found that individuals use more surface acting with non‐close others (vs. close others) and when they perceive situations as more significant. Additionally, surface acting was positively associated with negative affect. While being East Asians marginally predicted higher levels of surface acting, this effect became non‐significant when contextual factors were considered. The positive relationship between surface acting and negative affect did not differ across cultures. This study is novel in examining surface acting across various daily contexts beyond work, revealing contextual variations. We believe it contributes to expanding the emotion regulation literature on response modulation.