Introduction: During the COVID-19 pandemic governments worldwide applied legal sanctions to ensure compliance with pandemic-related restrictions on movement/social gathering. Reportedly sanctions such as fines were disproportionately issued. Our study extends understandings of how COVID-19 fines were issued to people who use drugs and the impact this had on their lives. Methods: This mixed methods study involved participants of two prospective observational cohort studies (n=2,156) of people who drugs, in Victoria, Australia. We analysed: 1) COVID-19-related quantitative survey responses; 2) in-depth interview transcripts of 76 cohort participants; and 3) brief follow-up interviews with participants who had received COVID-19 fines. Key Findings: Participants observed increased police presence in street-based drug markets and poorer neighbourhoods where they lived/spent time. Many believed policing practices were discriminatory and targeted. Thirty-eight participants received fines for non-compliance of COVID-19 restrictions - not wearing facemasks, travelling outside 5km-restriction zones, or being outdoors for “non-essential” purposes. Although some breached laws to purchase drugs, when fined some were homeless or travelling to get methadone or sterile injecting equipment with documentation proving they required these services. All said they lacked funds to pay the fines; although some applied to have them waived, few have have been successful, potentially impacting future criminal justice trajectories. Conclusion: Findings highlight how COVID-19 legal sanctions were differentially directed towards people who use illicit drugs in arbirtrary and inconsistent ways; an approach that worked to further criminalise and marginalise.