<p>Identifying the spiritual needs of older adults with chronic diseases and providing targeted care are essential for improving overall care quality. However, no culturally adapted and psychometrically validated Chinese version of the Spiritual Needs Questionnaire (SpNQ-20) is currently available for this population. This study aimed to translate and culturally adapt the Spiritual Needs Questionnaire (SpNQ-20) into Chinese and evaluate its psychometric properties. A cross-sectional study was conducted from May to July 2025 in two phases: (1) forward translation, back translation, cross-cultural adaptation, and pilot testing; and (2) psychometric validation among 1078 older adults with chronic diseases. The total sample was randomly divided into two independent subsamples for exploratory and confirmatory factor analyses. Validity was evaluated through content, construct, and concurrent validity analyses, whereas reliability was assessed using internal consistency, split-half reliability, and test–retest reliability. The final Chinese version of the SpNQ-20 retained 20 items across four dimensions. Content validity was satisfactory (S-CVI = 0.800; I-CVI = 0.923–1.000). Exploratory factor analysis supported the original four-factor structure, and confirmatory factor analysis demonstrated acceptable model fit (χ²/df = 2.155, RMSEA = 0.073, CFI = 0.916, TLI = 0.911, IFI = 0.916, GFI = 0.923). The scale demonstrated satisfactory concurrent validity (r = 0.713, <i>P</i> &lt; 0.01), excellent internal consistency (Cronbach’s α = 0.964), split-half reliability (0.945), and test–retest reliability (0.912). The Chinese version of the SpNQ-20 demonstrated satisfactory validity, excellent reliability, and good cross-cultural applicability, providing a reliable and culturally appropriate instrument for assessing the spiritual needs of older adults with chronic diseases and supporting spiritual care.</p>