The COVID-19 pandemic significantly impacted sexual and reproductive health and rights. Nepal implemented a nationwide lockdown in March 2020, limiting population movement and service access. The 36 clinics run by Marie Stopes Nepal (MSN) closed for varying periods at the beginning of lockdown. This study assesses the impact of lockdown and associated clinic closures on abortion services within MSN's network. An interrupted time-series analysis of clinic-level MSN data compared abortion service use in the pre-closure and post-reopening periods, focusing on the following outcomes: number of abortion care visits, proportion of abortion-related visits, gestational age at time of abortion care and demographics of patients accessing abortion care. Subsequent meta-analyses combined clinic-level results to generate outcome-specific pooled effect estimates. As MSN clinics reopened, during ongoing wider lockdown, weekly visits for abortion care decreased by 37% on average, but abortion increased as a proportion of services post-reopening (OR: 1.53) compared with pre-closure, with no evidence of a change in the proportion of higher gestation abortions. The demographic profile of abortion care clients was altered, with post-reopening clients more likely to have completed primary education (OR: 1.54) and be aged 25 years or older (OR: 1.31) compared with pre-closure clients. COVID-19 lockdown and associated clinic closures reduced the absolute number of abortion services provided within MSN's network, impacting the composition of service provision. Reductions in safe abortion and wider SRH access will have wide-ranging consequences, curtailing crucial reproductive rights. Policy-makers must ensure ongoing abortion access to protect rights and ensure access.