Background/Objectives: Basic psychological needs are essential for fostering motivation, self-regulated behaviors, and overall well-being. For cancer survivors, fulfilling these needs is crucial for coping with the various challenges of survivorship and for enhancing psychosocial health. This study aimed to assess the validity and reliability of the Korean version of the Basic Psychological Needs Satisfaction and Frustration Scale (K-BPNSFS) in a cancer survivor population. Methods: A cross-sectional design was employed, involving 367 community-dwelling cancer survivors. Construct validity was assessed using confirmatory factor analysis with multiple fit indices, while convergent validity was examined through Pearson’s correlation coefficients. Reliability was evaluated using internal consistency, inter-item correlations, and item-total correlations. Results: The findings confirmed a robust six-factor structure of the K-BPNSFS, which includes satisfaction and frustration dimensions corresponding to autonomy, relatedness, and competence needs. Convergent validity was supported by significant correlations with relevant constructs, aligning with the scale’s theoretical underpinnings. Reliability analysis demonstrated high internal consistency across all dimensions, with strong Cronbach’s alpha values and substantial item-total and inter-item correlations. Conclusions: This study establishes the K-BPNSFS as a valid, reliable, and culturally relevant instrument for assessing the basic psychological needs of Korean cancer survivors. Application of this scale provides critical insights into the unique psychological needs of this population, supporting the development of targeted healthcare strategies to enhance intrinsic motivation, self-care, and overall quality of life.