Long non-coding RNAs (lncRNAs) have key roles in tumor development and the progress of many cancers, including breast cancer (BC). This study aimed to explore for the first time the association of the migration/differentiation-associated lncRNA SENCR rs12420823C/T variant with BC risk and prognosis. Genotyping was carried out for 203 participants (110 patients and 93 controls) using the TaqMan allelic discrimination technique. The corresponding clinicopathological data, including the recurrence/survival times, were analyzed with the different genotypes. After adjustment by age and risk factors, the T/T genotype carrier patients were more likely to develop BC under homozygote comparison (T/T vs. C/C: OR = 8.33, 95% CI = 2.44–25.0, p = 0.001), dominant (T/T-C/T vs. C/C: OR = 3.70, 95% CI = 1.72–8.33, p = 0.027), and recessive (T/T vs. C/T-C/C: OR = 2.17, 95% CI = 1.08–4.55, p < 0.001) models. Multivariate logistic regression analysis showed that the T/T genotype carriers were more likely to be triple-negative sub-type (OR = 2.66, 95% CI = 1.02–6.95, p = 0.046), at a higher risk of recurrence (OR = 3.57, 95% CI = 1.33–9.59, p = 0.012), and had short survival times (OR = 3.9, 95% CI = 1.52–10.05, p = 0.005). Moreover, Cox regression analysis supported their twofold increased risk of recurrence (HR = 2.14, 95% CI = 1.27–3.59, p = 0.004). Furthermore, the predictive nomogram confirmed the high weight for SENCR rs12420823*T/T and C/T genotypes in predicting recurrence within the first year. The Kaplan–Meier survival curve demonstrated low disease-free survival (T/T: 12.5 ± 1.16 months and C/T: 15.9 ± 0.86 months versus C/C: 22.3 ± 0.61 months, p < 0.001). In conclusion, the LncRNA SENCR rs12420823*C/T may be associated with an increased risk of BC in women and could be a promising genetic variant for predicting recurrence and survival.