In an increasingly globalized and digitally mediated world, bilingual communication has become central to everyday interactions, particularly in linguistically diverse societies such as Saudi Arabia. English-Arabic code-mixing is widespread across generations; however, existing research has largely focused on younger speakers or specific contexts like education, leaving a gap in understanding how bilingual practices vary by age. This study investigates generational differences in English-Arabic code-mixing among bilingual speakers in Saudi Arabia and explores linguistic and social factors influencing younger speakers’ practices. Using a mixed-methods design, the study collected both quantitative and qualitative data from 89 participants across three age groups (16–30, 31–45, and 46–60) through a questionnaire. Findings revealed significant generational differences: older and middle-aged participants reported prevalent code-mixing in professional and peer settings, while younger speakers used it more selectively and contextually. Analysis of open-ended responses from younger participants highlighted identity expression, audience awareness, lexical gaps, and digital media as key drivers of code-mixing. These findings challenge assumptions that younger speakers code-mix more, suggesting instead a shift toward intentional, socially informed bilingual communication. The study contributes to sociolinguistic literature by emphasizing the evolving role of digital platforms, peer dynamics, and intergenerational norms in shaping bilingual practices across multilingual contexts.