Aim: To examine breast cancer perception, health-promoting lifestyle behaviours, and screening practices, and their sociodemographic and psychosocial correlates, among women in Abha, Saudi Arabia. Methods: A cross-sectional survey of 1,002 women aged ≥18 years in Abha (May–December 2025), recruited online through social media and instant messaging. Validated Arabic versions of the Breast Cancer Perception Scale (BCPS) and HPLP-II were self-administered online, with self-reported breast self-examination (BSE), clinical breast examination (CBE), and mammography history. Multiple linear regression identified predictors of HPLP-II and BCPS scores. Results: Perceived knowledge (3.64 ± 1.05), treatment belief (3.43 ± 0.77), fear (3.25 ± 1.30), and perceived risk (3.40 ± 0.89) were moderately high; perceived need for health checks (2.78 ± 1.23) and stigma (2.89 ± 1.14) were lower. HPLP-II mean was 2.63 ± 0.46 (spiritual growth highest 2.96 ± 0.50; physical ac-tivity lowest 2.23 ± 0.60). Ever-screening: BSE 61.1% (95% CI 58.1–64.1), CBE 22.5% (95% CI 20.0–25.1), mammography 12.8% (95% CI 10.8–14.8). Perceived knowledge (β = 0.059), treatment belief (β = 0.120), and stigma (β = 0.058) were positively, and perceived need for health checks (β = −0.259), perceived risk (β = −0.130), and fear (β = −0.028) negatively, associated with HPLP-II. Married women had higher lifestyle and perception scores; more educated and publicly employed women had higher perception scores. Conclusion: Despite moderately high perceived knowledge, clinical screening particularly mammography remains very low, and physical activity, a modifiable breast cancer risk factor, is the weakest lifestyle do-main. Awareness alone does not translate into screening; interventions should address fear and symptom-contingent care-seeking, embed screening referral in primary care, involve families, and promote culturally appropriate physical activity.