This study explores the metaphorical and metonymical expressions of sadness and joy in French idiomatic expressions, collected from various media sources and YouTube channels. Using a qualitative research design, it applies the Extended Conceptual MetaphorTheory to analyze how these emotions are conceptualized through image schemas, domains, and mental spaces. A type-based approach is used to categorize  the  source  domains  underlying  these  metaphors.  Metaphors  were  identified  using  the Metaphor  Identification  Procedure,  while  conceptual  metaphor  extraction  followed  a  structured approach. Inter-rater reliability measures ensured the objectivity of the analysis. The findings reveal that French   idioms   conceptualize   sadness   through   metaphors   such   as   having   an   unwelcome   insect (cockroach), grinding black thoughts, and having one’s spirits in one’s socks, whereas joy is expressed as being elevated with spiritual undertones and infused with vibrant colours like pink. Metonymies were also found where physiological, metaphorical, and expressive responsesstand for emotions, as seen in Je ne suis pas dans mon assiette, Mon cœur saute,  and Je pleure de joie.  Comparative  analysis  with  English, Chinese, and Japanese shows both universal patterns, such as sadness as bad taste and happiness as up, and  culture-specific  variations  in  emotional  conceptualization.  The  study  contributes  to  cognitive linguistics  and  cross-cultural  metaphor  research,  demonstrating  how  language,  culture,  and  cognition interact in shaping emotionalexpressions and providing insights for language learning and intercultural communication.​