Background: Extended, more effective breast cancer (BC) treatments have increased the prevalence of long term survivors. We investigated the risk of late breast cancer recurrence (BCR), 10 years or more after primary diagnosis, and associations between patient and tumor characteristics at primary diagnosis and late BCR up to 32 years after primary BC diagnosis. Methods: Using the Danish Breast Cancer Group clinical database, we identified all women with an incident early (non-distant metastatic) BC diagnosed during 1987–2004. We restricted to women who survived 10 years without a recurrence or second cancer (10-year disease-free survivors) and followed them from 10 years after BC diagnosis date until death, emigration, second cancer, or December 31, 2018. We calculated incidence rates (IRs) per 1,000 person-years and cumulative incidences for late BCR, stratifying by follow-up time, patient- and tumor characteristics. Using Cox regression, we calculated adjusted hazard ratios for late BCR accounting for competing risks. Findings: Among 36,924 women with BC, 20,315 became 10-year disease-free survivors. Of these, 2,595 developed late BCR (IR=15·5 per 1,000 person-years, 95%CI=14·9-16·1; cumulative incidence=17%) from year 10 to 32 after primary diagnosis. The rate of late BCR was highest 10-12 years after diagnosis (IR=22·1 per 1,000 person-years, 95%CI=20·9-23·4). Tumor size >20mm, lymph node positive disease, grade I/II, and estrogen receptor positive (ER+) tumors were associated with increased cumulative incidences and hazards for late BCR. Interpretation: The risk of late BCR was highest in year 10-12 after primary diagnosis, but recurrences continued to occur up to 32 years after primary diagnosis. Particularly women with high lymph node burden, larger tumor size, lower grade, and an estrogen receptor positive tumor had increased risk of late recurrence. Funding Statement: The Danish Cancer Society (“Knaek Cancer” R147-A10100) and Aarhus University. Declaration of Interests: Dr. Ejlertsen reports: Nanostring Technologies, Inc. (grant: institutional), Novartis (grant:294 institutional), and Roche (grant: institutional), Astrazeneca (grant: institutional), Oncology Venture (grant: institutional), Pfizer (grant: institutional), Samsung (grant: institutional). Dr. Christiansen reports personal fees from Roche Denmark, non-financial support from Roche Denmark, outside the submitted work. Dr. Lash reports personal fees from Amgen, non-financial support from Amgen, outside the submitted work. Dr. Mellemkjaer reports an immediate family member has an employment at Novo Nordisk. An immediate family member owns stocks in Novo Nordisk. No other potential conflicts of interest were reported. Ethics Approval Statement: This study was approved by the Danish Breast Cancer Group and the Danish Data Protection Agency (Aarhus University, J. no. 2016-051-00001, record number 552) and adheres to the General Data Protection Regulations. The study is based on routinely collected registry data and according to Danish regulations does therefore not require separate ethical approval.