PurposeCaveolin-1 (CAV1) has been implicated in breast cancer oncogenesis and metastasis and may be a potential prognosticator, especially for non-distant events. CAV1 functions as a master regulator of membrane transport and cell signaling. SeveralCAV1SNPs have been linked to multiple cancers, but the prognostic impact ofCAV1SNPs in breast cancer remains unclear. Here, we investigatedCAV1polymorphisms in relation to clinical outcomes in breast cancer.MethodsA cohort of 1017 breast cancer patients (inclusion 2002–2012, Sweden) were genotyped using Oncoarray by Ilumina. Patients were followed for up to 15 years. Five out of sixCAV1SNPs (rs10256914, rs959173, rs3807989, rs3815412, and rs8713) passed quality control and were used for haplotype construction.CAV1genotypes and haplotypes in relation to clinical outcomes were assessed with Cox regression and adjusted for potential confounders (age, tumor characteristics, and adjuvant treatments).ResultsOnly one SNP was associated with lymph node status, no other SNPs or haplotypes were associated with tumor characteristics. TheCAV1rs3815412 CC genotype (5.8% of patients) was associated with increased risk of contralateral breast cancer, adjusted hazard ratio (HRadj) 4.26 (95% CI 1.86–9.73). Moreover, the TTACA haplotype (13% of patients) conferred an increased risk for locoregional recurrence HRadj2.24 (95% CI 1.24–4.04). No other genotypes or haplotypes were associated with clinical outcome.ConclusionCAV1polymorphisms were associated with increased risk for locoregional recurrence and contralateral breast cancer. These findings may identify patients that could derive benefit from more tailored treatment to prevent non-distant events, if confirmed.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10549-023-06919-x.